The books by NCERT act as good references for exam preparation but not sufficient. These books will definitely help you in understanding the core concepts of various subjects but these will not help in advance problems. Hence, students shall refer to reference books to understand the higher difficulty level’s problems. However, textbooks must not be avoided as these help to ace in the MCQ section as nearly 60-70 percent MCQ type questions come directly from these textbooks. Apart from the books, sample papers and previous years question papers are absolutely helpful for entrance level examinations like JEE Main, Olympiad, NEET etc.