I am a B.Tech paper 1 JEE, 1st attempt student. Which subjects should I focus on?

Better to concentrate on chemistry and physics and try to students easy chapters in maths 

If this is your JEE 1st attempt, then don't be stressed about it . Try to take it easy .Out of physics, chemistry, and maths you should have a strong command over 2 subjects and prepare easy topics of third subject . For JEE Mains you just need to have a basic knowledge of any topic . PYQs help a lo