I want to know which lesson consists how many questions in JEE MAINS of 2021

Hello student as of now the authorities hasn't released any new syllabus notification but as per our HRD Minister Mr Ramesh Pokhriyal Nishank the syllabus of Jee main 2021 will reduce because of the lockdown pandemic covid-19 situation.
Careers360 Ceo Mr Maheshwer Peri interacted and did a live session with . Uma Sankar Manchella (All India IIT Coordinator And Senior Maths Lecturer, Sri Chaitanya Educational Institutions)about the impact of reduced syllabus of Jee main 2021, refer to the link mentioned below and watch it - https://youtu.be/NhzI5qRd-_w

Even earlier its difficult to predict exact number of questions chapter wise as it's an entrance examination you need to prepare thoroughly the whole syllabus to cover it well as a single question might need various concepts from multiple chapters.

Prefer NCERT to build your basic concept and make sure you do each and every example and exercise questions of Ncert before jumping to a reference book, after completing ncert thoroughly refer to your coaching material or any reference book as mentioned below -
OP TONDON CHEMISTRY
Rd Sharma Mathematics
Arihant practice book for Jee main
Concept of physics by HC VERMA
JDLEE Chemistry

You can also subscribe to careers360 knockout package for preparing and qualifying the entrance examination, it offer you 100 percent money back guarantee if you do not qualify - https://learn.careers360.com/knockout-jee-main-april/

Feel free to comment if you have any doubt
Good luck