Hello,

I would like to tell you NCERT is most important but remember NCERT is not sufficient.
Because the paper is made by CBSE and their syllabus is NCERT.
But some questions Come other than the NCERT.
By the studying NCERT thoroughly from cover to cover you can surely get 280 to 300 marks
But If you want to get a medical seat in a reputed govt college then You need to score 330 + in biology. So to score 330+ you need to prefer some reference book.
Also to score this much you need to solve lots of MCQs and take mock tests regularly. Then definitely you will be able to score at least 330+ marks.
Hope this helps.

You can score above 60 (out of 70) if you are thorough with the concepts. Reading between lines is a must for both the subjects.