NCERT or SCERT Books are the base for any examination. The language used is simple, lucid, and self-explanatory. Based on your command of the subjects, you can selectively choose NCERT books. There may or may not be direct questions from these books. But These are like foundations. Without a foundation, no floors of a building can be built.
Books of Classes VI to XII are helpful. All books are not required to study. The books are categorized based on the subjects. You can choose what to study based on your command of each subject. The following NCERT books are sufficient for the subjects mentioned for your foundation. You can download all these books from the Official NCERT Website for free.
The following books are the most valuable to read from NCERT. If you don’t have time (Ex: If you are a working professional), then complete reading of these books instead of all NCERT books. Then go for reading standard books.
General Science
Economy and Development
Geography and Environment
History and Culture