ArcGIS Pro 3.0 API Reference Guide
ArcGIS.Core.CIM Namespace / CIMTableField Class / SortOrder Property

SortOrder Property (CIMTableField)
Gets or sets the zero based sort order. -1 indicates field isn't used for sorting.
Syntax
public int SortOrder {get; set;}
Requirements

Target Platforms: Windows 11, Windows 10, Windows 8.1

ArcGIS Pro version: 2.1 or higher.
See Also