Hello,

See, the paper for JEE Mains is totally unpredictable but still we can have an idea of the questions which have higher weightage than the others in Chemistry by looking at past few years papers. In Chemistry, the topics with very high weightage are P block, D and F blocks, Atomic structure, Solid state, Electrochemistry, Thermodynamics and Thermochemistry, Coordination Chemistry, Chemical Bonding and the whole Organic Chemistry from Class 11th and 12th. Topics which have lesser weightage are Chemistry in everyday life, Polymers, Environmental Chemistry. But please note the fact that from JEE Point of view, each and every topic is important and you never know which part can be scoring for you, so better to study Chemistry NCERT thoroughly for better understanding of the concepts.

I hope it helps. For any further queries, ask me in the comments.