Dear student,

NCERT is one of the best books for Chemistry . If you are preparing for both JEE Mains and JEE Advanced, then NCERT is the very basic book to start with. For JEE Mains, this book is 80% enough. Just read it thoroughlly. For the remaining portion, you can follow some other books of chemistry  like OP Tondon Chemistry , etc. For JEE Advanced ,NCERT is not so enough. You need some other books like, Physical Chemistry by RC Mukhrjee , Organic by SKM etc.

But let me clear you, that first of all start with NCERT book. First complete this book. Only then move to other books. Without completing NCERT, don't go for any other book. And for JEE exams, solve as much previous year papers as you can.

Hope this helps.