If you are serious about your preparation for medical entrance exam NEET and want to be a doctor. First and foremost do self-study and focus on your weak areas. For coaching, you can go directly to Kota Allen as I know many from Dhanbad, Giridih, Jamshedpur who have gone to Allen Kota and serious prepare themselves for NEET. 

Self Study has no replacement. With the help of the internet, you can learn anything and can clear any doubts on online forums.