Well there are two cases here
- You are in 11 th standard .
- You have dropped a year.
Since you haven’t specified, I’ll take each case.
For Case 2: Choose any city.
Kota , Delhi , Hyderabad or anywhere where the lodgings and food is cheap and reputed coaching centers are available.
For Case 1 : Delhi it is.
I’ll tell you why. First and foremost it has all the good coaching centers. The Kalu Sarai area of South Delhi is in fact a coaching hub where students from all over India come for IIT JEE preparation.