Hello,

Solving previous year question papers will help you alot. It will help you to understand your preparation level and help you to understand the exam pattern. You will increase your speed and accuracy but along with solving previous year question papers i would suggest you to solve question from NCERT text books that will help you alot in your preparation.

If you have completed your NCERT or the JEE Mains syllabus , then you might solve many question papers in order to improve your time management and problem skills . But if you practice questions from NCERT, it would also help you much . So you should try to practice a lot and should not only stick to the previous year question papers.  But try to practice as much as possible .