Hi Viswasundaram !
Cracking any competitive examination completely depends upon your strategy. The branches for ESE examination are :-
1) Mechanical Engineering
2) Civil engineering
3) Electrical Engineering
4) Electronics and Telecommunication Engineering
it doesn't matter if you are graduate in btech IT there are only four branches in IES i.e CIVIL engineering
mechanical engineering
electrical engineering
electronics and communication engineering
you just need to be a engineering graduate irrespective of your branch you can choose any of these four branches and write IES exam
GOOD LUCK!