hey Manjunath,

There is a division of chapters and module in JEE mains Chemistry. The topic which usually comes on paper are:

• Purification and Characterization of Organic Compounds
• Some Basic Principles of Organic Chemistry
• Hydrocarbons
• Organic Compounds Containing Halogens
• Organic Compounds Containing Oxygen
• ALCOHOLS, PHENOLS, AND ETHERS
• Organic Compounds Containing Nitrogen
• Polymers
• Biomolecules
• Chemistry In Everyday Life
• Principles Related to Practical Chemistry

for more details go to https://engineering.careers360.com/articles/jee-main-chemistry-syllabus

hope that helps all the best