Hello,

You should plan a proper strategy to crack IIT JEE Advanced. You should devote proper time for your studies and manage proper time between the three subjects.
You should give more time to mathematics as it is it's basic requirement and it requires a lot of practice. Inst-ed of doing many question in Physics you should try to do different types of questions as they will help you to build your thinking skills. You should be thorough with chemistry as it is the least time consuming in examination and this will help you to think for tricky questions of Maths and physics in Exam.

You should solve previous years question papers for proper practice and time management you can try and give mock tests to know your weak areas. Preparing for JEE Advanced requires shear will and hard work.

You can refer this link for more information regarding cracking JEE.

https://engineering.careers360.com/articles/16-steps-crack-iit-jee

All the Best.