Hi Anandv,

I will not advice to neglect any chapter for JEE Examination, but I have listed out some topics with the highest weightage in JEE Main 2020:-

@Physics

• Modern Physics - 20 marks
• Heat and Thermodynamics - 12 marks
• Optics - 12 marks
• Current Electricity - 12 marks
• Electrostatics - 12 marks
• Magnetics - 8 marks

@Chemistry

• Transition Elements and Coordination Chemistry - 12 marks
• Periodic table and Representative Elements - 12 marks
• Thermodynamics And Gaseous State - 8 marks
• Atomic Structure - 8 marks
• Chemical Bonding - 8 marks
• Chemical And Ionic Equilibrium - 8 marks
• Solid State And Surface Chemistry - 8 marks
• Nuclear Chemistry And Environment - 8 marks

You may refer to this article for more information about JEE Main Syllabus with Weightage.

Feel free to ask doubts in the Comment Section.

I hope this information helps you.

Good Luck!