Both modes are definitely available to you and thousands of candidates qualify jee main using either modes coaching center just provides you an organized way to move about but in self study you will have to do every thing on your own if you do self study then in case of doubts you will have no one to ask from but in coaching you will have your tutors but if there is a will there is a way so at the end I would recommends you to join a coaching center as why to lag behind others initially when you have option of not to but in case you want to do self study only then join any test series of a coaching center as it will keep you organized hope this helps.