Coaching and self study both have advantages and disadvantages of their own.
coaching gives you better conceptual understanding, immediate doubts clarification available by the teachers, forming study groups and discussing doubts with them.And there may be financial problem for those who cannot afford the high prices for the institute coaching and staying in hostel may have effect on your health, and also the disturbance in hostel due to other hostel mates.
and coming to good coaching institutes I found ACE and MADEEASY are good coaching centres.
In self studying you can learn from standard books, NPTEL lectures, youtube videos etc., if you already have good knowledge in the topics, you can go for self studying, where you should not forget the revision and test series part which play a major role in success of a candidate preparing for the examination.