Main reference for Neet examination is NCERT textbook. Human physiology is an important topic with high weightage in NEET examination. It is a portion in class 11th NCERT textbook. It is expected that there will be almost 12 to 16 questions from this portion. It has 18 to percentage of weightage.

You can check this in the link https://www.google.com/amp/s/medicine.careers360.com/articles/neet-chapter-wise-weightage-and-important-topics/amp here is a chapter wise weightage

* Diversity of Living Organisms :- 14%

* Structural Organisation in Plants & Animals :- 5 %

* Cell: Structure and Function :- 9 %

* Plant Physiology :- 6 %

* Human Physiology :- 20 %

* Reproduction :- 9 %

* Genetics and Evolution :- 18 %

* Biology and Human Welfare :- 9 %

* Biotechnology and its Applications :-4%

* Ecology and Environment :- 6 %