public ReconcileResult Reconcile( 
   ReconcileOptions reconcileOptions,
   PostOptions postOptions
)

public void GetVersionConflictsInfoInUpdateDeleteType(ServiceConnectionProperties featureServiceConnectionProperties, string featureClassName)
{
  // To illustrate the conflict between versions,
  // the feature is updated in the child version and deleted in the parent version.

  long featureObjectIDForEdit = Int64.MinValue;

  // Get branch versioned service
  using (Geodatabase fsGeodatabase = new Geodatabase(featureServiceConnectionProperties))
  using (VersionManager versionManager = fsGeodatabase.GetVersionManager())
  using (Version defaultVersion = versionManager.GetDefaultVersion())
  using (Geodatabase defaultGeodatabase = defaultVersion.Connect())
  using (FeatureClass defaultFeatureClass = defaultGeodatabase.OpenDataset<FeatureClass>(featureClassName))
  using (FeatureClassDefinition defaultFeatureClassDefinition = defaultFeatureClass.GetDefinition())
  {
    // Create a feature in the default version to edit in a branch
    defaultGeodatabase.ApplyEdits(() =>
    {
      using (RowBuffer rowBuffer = defaultFeatureClass.CreateRowBuffer())
      {
        rowBuffer["NAME"] = "Loblolly Pine";
        rowBuffer["TREEAGE"] = 1;
        rowBuffer[defaultFeatureClassDefinition.GetShapeField()] = new MapPointBuilderEx(new Coordinate2D(1, 1),
          SpatialReferenceBuilder.CreateSpatialReference(4152, 0)).ToGeometry();

        using (Feature feature = defaultFeatureClass.CreateRow(rowBuffer))
        {
          featureObjectIDForEdit = feature.GetObjectID();
        }
      }
    });

    // Add newly created feature in the filter
    QueryFilter queryFilter = new QueryFilter { ObjectIDs = new List<long> { featureObjectIDForEdit } };

    // Create a branch version
    VersionDescription versionDescription = new VersionDescription("UpdateDeleteConflictType",
      "Update-Delete version conflict type", VersionAccessType.Private);

    // Edit the feature in the branch 
    using (Version editVersion = versionManager.CreateVersion(versionDescription))
    using (Geodatabase branchGeodatabase = editVersion.Connect())
    using (FeatureClass featureClass = branchGeodatabase.OpenDataset<FeatureClass>(featureClassName))
    using (RowCursor rowCursor = featureClass.Search(queryFilter, false))
    {
      branchGeodatabase.ApplyEdits(() =>
      {
        while (rowCursor.MoveNext())
        {
          using (Row row = rowCursor.Current)
          {
            row["TREEAGE"] = 100;
            row["NAME"] = $"{row["Name"]}_EditInBranch";
            row.Store();
          }
        }
      });

      // Delete the feature from the default version
      defaultFeatureClass.DeleteRows(queryFilter);

      // Reconcile options
      ReconcileOptions reconcileOptions = new ReconcileOptions(defaultVersion)
      {
        ConflictResolutionType = ConflictResolutionType.FavorEditVersion,
        ConflictDetectionType = ConflictDetectionType.ByRow,
        ConflictResolutionMethod = ConflictResolutionMethod.Continue
      };

      // Reconcile with default
      ReconcileResult reconcileResult = editVersion.Reconcile(reconcileOptions);

      // Check for conflicts
      bool hasConflictsReconcileResults = reconcileResult.HasConflicts;
      bool hasConflictsAfterReconcile = editVersion.HasConflicts();

      // Fetch conflicts
      IReadOnlyList<Conflict> conflictsAfterReconcile = editVersion.GetConflicts();

      // Iterate conflicts
      foreach (Conflict conflict in conflictsAfterReconcile)
      {
        // Object ID of row where conflict occurs
        long objectId = conflict.ObjectID;

        ConflictType conflictType = conflict.ConflictType;

        IReadOnlyList<FieldValue> ancestorVersionValues = conflict.AncestorVersionValues;
        object nameAncestor = ancestorVersionValues.FirstOrDefault(f => f.FieldName.Contains("NAME")).Value;
        object treeAgeAncestor = ancestorVersionValues.FirstOrDefault(f => f.FieldName.Contains("TREEAGE")).Value;

        IReadOnlyList<FieldValue> childVersionValues = conflict.ChildVersionValues;
        object nameChild = childVersionValues.FirstOrDefault(f => f.FieldName.Contains("NAME")).Value;
        object treeAgeChild = childVersionValues.FirstOrDefault(f => f.FieldName.Contains("TREEAGE")).Value;

        IReadOnlyList<FieldValue> parentVersionValues = conflict.ParentVersionValues;

        IReadOnlyList<Field> originalFields = defaultFeatureClassDefinition.GetFields();

        string datasetName = conflict.DatasetName;
      }
    }
  }
}

public void ReconcileAndPost2(Geodatabase geodatabase)
{
  // Get a reference to our version and our parent
  if (geodatabase.IsVersioningSupported())
  {
    using (VersionManager versionManager = geodatabase.GetVersionManager())
    using (Version currentVersion = versionManager.GetCurrentVersion())
    using (Version parentVersion = currentVersion.GetParent())
    {

      //// Create a ReconcileDescription object
      //At 2.x - 
      //ReconcileDescription reconcileDescription = new ReconcileDescription(parentVersion);
      //reconcileDescription.ConflictResolutionMethod = ConflictResolutionMethod.Continue; // continue if conflicts are found
      //reconcileDescription.WithPost = true;

      //// Reconcile and post
      //ReconcileResult reconcileResult = currentVersion.Reconcile(reconcileDescription);

      // ReconcileResult.HasConflicts can be checked as-needed

      // Create a ReconcileOptions object
      ReconcileOptions reconcileOptions = new ReconcileOptions(parentVersion);
      reconcileOptions.ConflictResolutionMethod = ConflictResolutionMethod.Continue; // continue if conflicts are found
      reconcileOptions.ConflictDetectionType = ConflictDetectionType.ByRow; //Default
      reconcileOptions.ConflictResolutionType = ConflictResolutionType.FavorTargetVersion;//or FavorEditVersion

      PostOptions postOptions = new PostOptions(parentVersion);
      //var postOptions = new PostOptions(); for default version
      postOptions.ServiceSynchronizationType = ServiceSynchronizationType.Synchronous;//Default

      // Reconcile
      ReconcileResult reconcileResult = currentVersion.Reconcile(reconcileOptions, postOptions);
      if (reconcileResult.HasConflicts)
      {
        //TODO resolve conflicts

      }

    }
  }
}

// Partial posting allows developers to post a subset of changes made in a version.
// One sample use case is an electric utility that uses a version to design the facilities in
// a new housing subdivision. At some point in the process, one block of new houses have been
// completed, while the rest of the subdivision remains unbuilt.  Partial posting allows the user
// to post the completed work, while leaving not yet constructed features in the version to be
// posted later. Partial posting requires a branch-versioned feature service using ArcGIS
// Enterprise 10.9 and higher

// Specify a set of features that were constructed
QueryFilter constructedFilter = new QueryFilter()
{
  WhereClause = "ConstructedStatus = 'True'"
};
// This selection represents the inserts and updates to the support
// structure feature class that we wish to post
using (Selection constructedSupportStructures = supportStructureFeatureClass.Select(constructedFilter, SelectionType.ObjectID, SelectionOption.Normal))
{
  // Specifying which feature deletions you wish to post is slightly trickier, since you cannot issue
  // a query to fetch a set of deleted features Instead, a list of ObjectIDs must be used
  using (Selection deletedSupportStructures = supportStructureFeatureClass.Select(
                                      null, SelectionType.ObjectID, SelectionOption.Empty))
  {
    deletedSupportStructures.Add(deletedSupportStructureObjectIDs);  //deletedSupportStructureObjectIDs is
                                                                     //defined as List<long>

    //Perform the reconcile with partial post
    //At 2.x - 
    //ReconcileDescription reconcileDescription = new ReconcileDescription();
    //reconcileDescription.ConflictDetectionType = ConflictDetectionType.ByColumn;
    //reconcileDescription.ConflictResolutionMethod = ConflictResolutionMethod.Continue;
    //reconcileDescription.ConflictResolutionType = ConflictResolutionType.FavorEditVersion;
    //reconcileDescription.PartialPostSelections = new List<Selection>() { constructedSupportStructures, deletedSupportStructures };
    //reconcileDescription.WithPost = true;

    //ReconcileResult reconcileResult = designVersion.Reconcile(reconcileDescription);

    ReconcileOptions reconcileOptions = new ReconcileOptions();//reconcile against Default
    reconcileOptions.ConflictDetectionType = ConflictDetectionType.ByColumn;
    reconcileOptions.ConflictResolutionMethod = ConflictResolutionMethod.Continue;
    reconcileOptions.ConflictResolutionType = ConflictResolutionType.FavorEditVersion;

    PostOptions postOptions = new PostOptions();//post against Default
    postOptions.PartialPostSelections = new List<Selection>() {
                    constructedSupportStructures, deletedSupportStructures };
    postOptions.ServiceSynchronizationType = ServiceSynchronizationType.Synchronous;

    ReconcileResult reconcileResult = designVersion.Reconcile(reconcileOptions, postOptions);

    //TODO process result(s)
  }
}