NCERT textbooks for Classes 11 and 12 are considered the most important study resources for NEET UG preparation. A large portion of the questions, especially in Biology and Chemistry, are either directly based on NCERT content or derived from concepts explained in these books. Students are strongly advised to thoroughly read, understand, and revise NCERT textbooks multiple times. Many toppers recommend mastering NCERT before referring to additional study materials or advanced reference books.