Hello dear student,

No it's not sufficient. You have to study from other study materials too because alone ncert can get you to score 300 but to come in merit you have to get those extra 30 or 40 marks that will make you different from others in the test . And give a increment to your rank. So you need to improve your concepts . Solve as many MCQ's you can and Also the previous year's question. 

Rest you can refer some other books that school ask you to buy like truemen's , pradeep's etc .

Dear Candidate

Yes, for theory the NCERT book for is the bible for Biology.

Make sure that you know the book cover to cover. Also, you should cover all the diagrams that are mentioned. You must supplement your preparation with NCERT at your fingertips - it is a very good book, then previous years papers and timely tests!

you will do well if you follow this in a disciplined way.