Hi,

JEE Mains 2021 includes the syllabus from Physics, Chemistry and Mathematics. You can get the detailed syllabus for these subjects along with the weightage from each unit from the following links:
Physics: https://engineering.careers360.com/articles/jee-main-physics-syllabus

Chemistry: https://engineering.careers360.com/articles/jee-main-chemistry-syllabus

Mathematics and weightage for each unit for all the subjects: https://engineering.careers360.com/articles/jee-main-syllabus-weightage

Attempt the online test series for JEE Mains accustomed according to the JEE Mains 2021 Exam pattern: https://learn.careers360.com/test-series-jee-main-april/