Hii Hafizur,

if you want to crack JEE main and your maths is weak,then you can crack it with Chemistry.

try to go through the NCERT chemistry(XI,XII).

and also go through the Physics of XI,XII.

and also solve last year questions as much as possible.it will definately help you.

some chapters of Mathematics are 10th based so you can go through them-

• Sets, relations and functions
• Matrices and determinants
• Complex numbers and quadratic equations
• Sequences and series
• Co-ordinate geometry
• Statistics and probability
• Trigonometry

for more tips please go through the link-

 https://engineering.careers360.com/articles/how-prepare-for-jee-main

hope you understand 

thank you 

Thank you for your question. 

Getting average marks in maths in boards is not a criteria in JEE. If you have 50% marks, that's enough to apply in the entrance examination. 

You can then improve on your mathematics and get the weakness out.

By average Number of questions asked in previous year JEE Main / Advanced Maths papers:

• Coordinate Geometry – 7 Questions were asked on an average every year in the JEE
• Continuity/ Differentiability, Limits – 3 Questions
• Complex No., Quadratic Equation – 3 Questions each
• Integral Calculus – 3 Questions
• Sequence and Series – 2 Questions
• Trigonometry – 2 Questions

Good luck