Hello Dheeraj,

It totally depends on you if you can manage your 12th class and preparation of JEE yes, then you can surely prepare. If you do so the you must be very punctual on studies as you are doing two things at the same time. There will be a lot of burden on you as you have to maintain both things.

If you don't want to do jee preparation with 12th then you can drop one year and study for jee.

Hope it helped you

Thank you