Hello,Avanti

NCERT is a great book to prepare for competitive exams like NEET,AIIMS etc,but it is not sufficient to score 600+. As the paper is made by CBSE and their main book is NCERT , so most question may come from that but probability of questions coming from outside is also high.So clear your basic concepts from NCERT, but also do refer other books.Also if you have joined some coaching class you might get a good study material from there as well.Practice as many as papers you can to score well.Below is the link provided to refer other books for better preparation:

https://medicine.careers360.com/articles/best-books-for-neet.

Hope your query is answered.

All the best