Hi @dhanshri_gavas. The lower left number 'Total Occurrences in Active Document' is the total number not only in the top level of the assembly, but also all that are in all of the sub assemblies also. That number can be obtained using something similar to the following. This is just a quickie example to show the number in a MsgBox.
Dim oADoc As AssemblyDocument = ThisDoc.Document
Dim oADef As AssemblyComponentDefinition = oADoc.ComponentDefinition
Dim iTotalOccsAllLevels As Integer = oADef.Occurrences.AllReferencedOccurrences(oADef).Count
MsgBox(iTotalOccsAllLevels.ToString, , "Occurrences Count")
As far as I know, that number should always be 1 in a part. And in a drawing, it will reflect all the data from all the models being referenced within the drawing. So if you have an assembly with number = 105, then you create a drawing for just that assembly, the drawing will show that same number.
Wesley Crihfield

(Not an Autodesk Employee)