Amar, if you can join any Coaching Centre for CA, that should be fine because you register with ICAI at an individual level and not on behalf of your College. For example, lets take CA Foundation. For being eligible for CA Foundation, you have to complete your 12th from any stream. Unlike your 10th and 12th, there are no regular colleges for CA. You have to register with ICAI for studying CA. And then you have to complete a mandatory 4 months study period to be eligible for appearing for CA Foundation. For this you can join any Coaching Centre or can study on your own. Having said that, because CA Exam and marking pattern are unique and the syllabus is difficult for someone  who comes from 12th, it is always advisable to join a Coaching Centre to complete the study period. That way you learn the intrinsic of the programme better than when you study on your own. Atleast for Foundation and Intermediate you should join some Coaching Centre. By the time you enter Finals, you wiil gain experience as to how to study on your own.