Hi Sanjay,
If you have greath depth od knowledge in Mathamatics, Physics and Chemistry you can crack JEE exam for getting admitted at IIT.

There are lot of crash courses, which you can attend and get prepared for JEE.
The exam is for 3 hours with 300 marks.By taking good number of mock tests, which you can do.

By taking the JEE 2020, wilo be a great experience, which will help you to improve better.
Hope this will help you.
Thank you