Спасибо! Нашел решение своей проблемы. Если кому надо вот код
Dim pMXD As IMxDocument
Set pMXD = ThisDocument
Dim pFlayer As IFeatureLayer
Set pFlayer = pMXD.FocusMap.Layer(0)
Dim pIndexes As IIndexes
Set pIndexes = pFlayer.FeatureClass.Indexes
Dim i As Long
Dim pIndex As IIndex
For i = 0 To pIndexes.IndexCount - 1
Set pIndex = pIndexes.Index(i)
MsgBox "Index " & i & " , Name" & pIndex.Name & " , unique " & pIndex.IsUnique & _
", FieldCount for this Index: " & pIndex.Fields.FieldCount & _
", FirstField: " & pIndex.Fields.Field(0).Name
Next