Hello Dear

As you said you are a student from Bengali medium then in such case inorder to take the coaching for that engineering entrance exams like WBJEE, IIT-JEE, COMEDK etc. you have to enter into the Institute's like Allen, Resonance, FIITJEE etc for your further preparation of these entrance exam such that you can be able to take the good College for your engineering and yaah there is a difference between the coaching and the engineering is that if you take the better coaching that mean better chances you have the take the good Colleges / Institute.

All the best