Hey Seema,

This is a very crucial question. To be very honest even if you go to coaching institutes they'll just tell you some tricks and tips. Ultimately you have to do self study only. NEET is purely based in NCERT text book. If you're thorough with the text book then you'll be able to answer 70-80% of the questions. I suggest you to take some home tuitions for Chemistry and Physics so that you can clear your doubts on time and join a test series in some coaching so that you can test yourself and prepare better.

I hope this helps you, good luck!