Short answer: Check the subject list for your class first, buy the current edition and consider a second hand copy only if the edition matches.
Confirm the subject list
Each class has its own set of textbooks. Confirm the list with your school, since optional subjects and language choices can differ.
Edition matters
NCERT revises books from time to time and syllabi are rationalised. A copy from a previous year may include chapters that are no longer taught, so match the edition with your school.
Second hand is fine when
Second hand NCERT books are good value when they are the current edition, complete and free of heavy marking. They are less suitable if you want to write answers in the margins.
Related: find NCERT books at low prices.
Frequently asked questions
Can I use an older NCERT book?
Only if the syllabus and edition have not changed. Check with your school before relying on an older copy.
Where can I find second hand school books?
Browse second hand school textbooks by class and board on Bookaao.