Change course of attack on Indian State (2,5)
I believe the answer is:
go about
'change course' is the definition.
(I've seen this before)
'attack on indian state' is the wordplay.
'attack' becomes 'bout' (eg a bout of flu).
'on' is a charade indicator (letters next to each other).
'indian state' becomes 'goa' (Goa is a state of India).
'bout' after 'goa' is 'GO ABOUT'.
'of' acts as a link.
(Other definitions for go about that I've seen before include "Begin to deal with" , "(Of ship) change course" , "turn at sea" , "Approach" .)