Hello

Coaching and self study both are important to clear jee main. In coaching they will guide you about the tricks , also your concepts will get clear. The  test series conducted by the coaching centre will also help you for the exam. From this you will learn the time management. But self study is also important . You have to practice more problems and work hard to clear the jee mains . By equal efforts of self study and coaching you can clear jee main exam.

Hope this helps

Regards