There are some topics which are not included in JEE Advanced, but they are there in JEE Main. I would like to tell you that there is no such topic or chapter in NCERT which is not in the syllabus of JEE Main. JEE Main includes each and every nook and corner from the NCERT books of Physics, Chemistry and Mathematics. So, I recommend you to not leave anything and cover the whole books to score good in JEE Main. All the best.