Exam

Choose the field in which you love to work and you have very much interest in it with curiosity. This will be very much beneficial for your career. Scopes and popularity in the fields keeps on changing according to demands. But if you have chosen the career of your interest, then you can become succ

Abhinandan, go to the following link:
http://www.juit.ac.in/admissions.php

Almost every branch of engineering needs the application of physics. But try to make him choose a branch in which your son would love to work and has very much interest in. This will make it very beneficial for his career.

No that can't be done as each candidate will be having a specific date and time which they would have already chosen during the slot booking. So I think, you cannot attend the examination as you have missed the date which you have selected.
Or you try to call the BITs admin regarding this query, but

Refer the below link for top colleges: https://www.shiksha.com/mba/ranking/top-mba-colleges-in-india/2-2-0-0-0

You can admission in LPU, JSS Noida and CU. You can check for NITs.