Hi Shina,
Try this formula
=MID(E11,(FIND(".",E11,FIND(".",E11,FIND(".",E11,FIND(".",E11)+1)+1)+1)+1),255)
E11 cell contains ur data ie., IND.A.4.08.0225
It will find 4 th dot always, and displays the next characters upto 255 characters
Hope this helps !!