As per my experience everyone who cracked neet said that read the ncert of biology as all the questions come from ncert... But reading ncert is nt easy because in one line there is given the information of 4 lines means before reading we should almost know very well about the chapter... Then we can understand what actually is in ncert... It is ture that all the things are in ncert but it is not easy to grab those all... The one line of ncert carries a huge knowledge... If we start reading it without knowing what actually it is then we can only understand the line meaning not the things or questions which actually are behind it... So first read the chapters from ur other sources well and then revise it from ncert...

See its very hard to define problems from NCERT and not from NCERT in subjects like Biology. But as per the experts and the toppers, 98% of the question in NEET comes from NCERT Biology. Thus you can see that there is a very good number coming from NCERT. Now from the past year analysis the weightage have been defined based on subject.

chapterwise weightage for NEET:

• 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.

To know more about NEET chapterwise analysis visit the link below:

https://medicine.careers360.com/articles/neet-chapter-wise-weightage-and-important-topics

I hope this answer helps. All the very best for your future endeavors!