JEE Main Scores

Hello Akansha,
Yes, why not! Everyone can secure a good rank provided you work in the right way with good efforts.
Syllabi of both CBSE and state board in classes 11&12 are the same which is NCERT class 11&12. Maybe the difficulty would be different as CBSE questions involve more complexity which is the basis of JEE exams. So it is believed that CBSE students would only crack the exam with a good rank. It's not like that.
First, you need to decide whether you are going to learn by self-preparation or by joining a good coaching center.
If you have such a guidance then it would be better as they will guide in the exact way to clear JEE. They will give timely test papers and analyze your performance which would help you a lot. they would also coach better (only in a good coaching center). With that, you can easily qualify JEE main and advanced but you need to work hard to get a top rank.
By self-preparation, it is easy to crack JEE main but for advanced it is advisable to have a coaching. As you would be restricted to certain books, you may not practice a variety of papers and varieties of questions.
Even though you can crack JEE main by giving mock test papers, solving previous year papers and having a strong grip on concepts. clearing JEE advanced by self-preparation is not that easy.
so decide for yourself and work hard with full dedication to crack JEE exams. I would advise you to join a good coaching centre.