Hey Vishal! 

For getting rank under 400 in jcece is not a hard task.you should go through the books

Thoroughly you should check the books

From the link https://engineering.careers360.com/articles/best-books-for-jee-main-2019/amp

Beside these books you must have to  solve previous year question papers as most of questions are copied from previous year papers. 

Hope this will be sufficient..