Hello!!

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Here are the most important chapters for JEE mains

Mathematics:

• Integration
• Differentiation
• Probability
• Three Dimensional Geometry
• Trigonometry

Physics:

• Mechanics
• Oscillations And Waves
• Rotational Motion
• Electrostatics
• Atoms And Nuclei
• Current Electricity

Chemistry:

• Organic Compounds Containing Oxygen
• Equilibrium
• Chemical Kinetics
• Transition Elements (d and f block)
• s-block Elements
• Chemical Bonding And Molecular Structure
• Some Basic Principles Of Organic Chemistry
• p-block Elements

You can kindly go through the link given below for more information:

https://engineering.careers360.com/articles/most-important-chapters-of-jee-main

Hope it helps!!

All the best!!