hey Ganesh ,NCERT books plays very important role in each and every competitive exams,specially in NEET an aiims exam.Ncert is generally used for basic superficial study of concepts and through which question comes atleast of 15 to 20 marks,so it is a plus point.In chemistry you will come across many NCERT question and you can directly answer them without hesitaion if you have mastered over NCERT books.

Hi ganesh, 

Yes ncert questions in books of physics and chemistry are beneficial because they will clear your basic and then you will be able to solve extra questions from some other extra books with your understanding of ncert books question. 

Just give somewhat time to ncert questions too. 

In aiims and neet questions come directly for ncert chapters and question so study it carefully. 

All the best.