Dear Nayak,

Cracking NEET is surely a big deal and not cakewalk for sure. You would have experienced this while writing NEET this year that the exam is very demanding and it needs all your time and concentration. 

NEET requires sheer dedication and intense hardwork to crack the exam. So, I would suggest you to take a drop for the preparation for NEET if you really want to pursue MBBS.

No you won't be required to submit any proof. And leaving Diploma won't be a trouble. 

hope you got your answer.

Good luck :)