Dear

You need to work hard if you want to pursue Engineering and want better opportunity then you should have good foundation in Maths and Physics subjects specially in this field and moreover every Engineering degree.

All the best

Dear Rohit
It's okay. But in B-Tech you don't have to worry about it. But keep in mind that physics is everything, you need to have some basic knowledge about it.
All the best. Hope, you'll board in mechanical soon.