Hello Tanushree!

NCERT is must if you are aiming at exams like paramedical, polytechnic, JEE, medical, etc

You must start your preparation with NCERT to know the concepts and keep one reference material only to consider when you are not understanding few things. After knowing the concepts, you will be required to solve as much problems as you can. You should solve previous year problems and question banks of paramedical for better grip.

But keep revising your NCERT in parallel.

All the best!