Dear Aspirant,

See here are some of the important  and scoring topics for IIT JEE for all 3 subjects-

https://engineering.careers360.com/articles/jee-main-important-topics-books

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

https://engineering.careers360.com/articles/most-easy-and-scoring-chapters-for-jee-main

https://engineering.careers360.com/articles/important-topics-for-jee-main-and-advanced

For Maths,

See for Maths PRACTICE is necessary but also you need to learn from your mistakes and rectify them.

After each and every mock test try to analyze it, see what mistakes you did, which question took longer time, which questions you could not attempt, try to figure out your weak areas.

You may also a separate note of all mistakes in mock test , so that you don't  repeat those.

For Maths theory is equally important with solving questions.

If you have a good grasp of theory you'll understand the problem very well, hence  finding the solution.

It happens to many students that the solution doesn't strike immediately, but for this you need to develop the particular aptitude & temperament.

For this try to solve variety of  problems , first go through solved examples  and then solve  some questions.

Refer RD Sharma for IIT JEE book (Vol 1 & Vol 2)

Try if you can find out some of your own ways of approach to similar kind of problems.

Also when you are doing some practice problems on a daily basis , try to do them with timer, have small targets that you have to complete this many problems in 30 mins or 1 hour or whatever feels achievable. This will counter your time pressure problem in Exam.

Check out:

https://engineering.careers360.com/articles/jee-main-preparation-tips

https://engineering.careers360.com/articles/jee-main-mock-test

https://learn.careers360.com/knockout-jee-main-april/

Hope this helps. ALL THE BEST!!