Hi,

Following are the important and high weightage chapters for Chemistry and Physics for NEET preparation-

CHEMISTRY-

• Organic Chemistry forms the bases of many chapters
• Thermodynamics- 9%
• Chemical bonding and atomic structure- 5%
• Equilibrium- 6%
• Solutions- 5%
• Electrochemistry- 4%
• Coordination compounds- 4%
• Alcohols, Phenols and Ethers- 8%
• Polymers, Chemistry in everyday life and biomolecules always have 1-2 questions each so they must be revised thoroughly-

PHYSICS-

• Optics- 10%
• Thermodynamics- 9%
• Electrostatics- 9%
• Current electricity- 8%
• Rotation- 5%
• Work, energy and power- 4%
• EMI and AC- 5%

Hope it helps!

Hello Aspirant,
See there is no any fixed criteria that how many chapters will have more weightage and will become more important so you need to prepare whole syllabus but as per the previous year's analysis I am mentioning down the weightage of each topic from all the 3 subjects. 
However you can check out the link given below for the list of some Do or Die chapters which are very important as per previous year papers :-
https://medicine.careers360.com/articles/do-or-die-chapters-for-neet/amp

For NEET 2022, complete chapter wise Wieghtage for each subject is described below :-

@Physics 
Physical-world and measurement-2%
Kinematics-3%
Laws of Motion-3%
Work, Energy and Power-4%
Motion of System of Particles and Rigid Body-5%
Gravitation-2%
Properties of Bulk Matter-3%
Thermodynamics-9%
Behaviour of Perfect Gas and Kinetic Theory-3%
Oscillation & Waves-3%
Electrostatics-9%
Current Electricity-8%
Magnetic Effect of Current & Magnetism-5%
Electromagnetic Induction & Alternating Current-8%
Electromagnetic Waves-5%
Optics-10%
Dual Nature of Matter and Radiation-6%
Atoms & Nuclei-3%
Electronic Devices-9%

@Chemistry
Basic Concepts of Chemistry-1%
Structure of Atom-2%
Classification of Elements & Periodicity in Properties-2%
Chemical Bonding and Molecular Structure-5%
States of Matter: Gases and Liquids-2%
Thermodynamics-8%
Equilibrium-6%
Redox Reactions-3%
s-Block Elements-2%
Some p-Block Elements-2%
Organic Chemistry: Basic Principles & Techniques-4%
Hydrocarbons-3%
Environmental Chemistry-2%
Solid State-2%
Solutions-5%
Electrochemistry-2%
Chemical Kinetics-3%
Surface Chemistry-2%
Isolation of Elements-2%
p-Block Elements-5%
d- and f-Block Elements-4%
Coordination Compounds-9%
Haloalkanes and Haloarenes-3%
Alcohols, Phenols and Ethers-4%
Aldehydes, Ketones and Carboxylic Acids-4%
Organic Compounds containing Nitrogen-2%
Biomolecules-3%
Polymers-3%
Chemistry in Everyday Life-2%

@Biology
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%

For complete details about important chapters and other weightage related information kindly check out the links given below :-
https://medicine.careers360.com/articles/neet-chapter-wise-weightage-and-important-topics

You can also check out NEET Knockout package for your preparation :-
https://learn.careers360.com/knockout-neet-may/

I hope this information helps you.
Good Luck!!