NTA conducts NEET in offline mode which means the question papers are not released and so it is difficult to check which questions have been asked from which book. But in general 98% of the questions in NEET come from NCERT books alone. But based on previous years of paper analysis weightage has been calculated for each topic. Human Physiology and Genetics have maximum weightage in NEET. Diversity of Living Organisms has 14% weightage. Structural Organisationi n Plants and Animals takes 5%. Plant Physiology has 6% and Cell Structure and Function has 9%. Human Physiology has 20% weightage. Reproduction chapter has 9% and Genetics and Evolution has 18% weightage. Biology and Human Welfare has 9% weightage. Biology and its application has 4% weightage and Ecology and Environment has 6% weightage.

Hello Shubha,

See CBSE has made the NEET exams so you can say that you can refer there books which are the Ncerts.

Talking about the syllabus mostly is from Ncerts like 75% from ncerts and remaining 25% from other books.

One should always be prepared to get 3–4 questions out of the syllabus in biology (They could or could not have a mention in NCERT. Mostly  Physics 90% question are related from ncerts.