Hey Uzma

NCERT books especially for Chemistry is a very good resource for JEE Mains, if a candidate reads the book thoroughly and gets the concepts perfectly along with solving all questions/exercises in the book then getting through JEE Mains question won't be difficult for the candidate.

But it is very rare that questions from NCERT directly appear in JEE Mains. This has been experienced very rarely by students in the past few years, the concepts and methods may match but getting a directly copied question is very difficult to find in JEE mains paper.

For further doubts, ask us.