JoSAA

It is not necessary to lock, it's automatically get locked.

If you get seat in 1st round, then you have to report. You don't have to submit any original documents but yes the photocopy one will be taken.

You can change your choices before automatic lock by JoSAA or by you. JoSAA automatically locks the choice fillup at the specified end time. So before locking you can edit, add, delete, update your choice fillup. After locking you can only change the preference order but that's only after 1st round.

Based on last year's ranking cut off, there is a good probability of you getting into Production Engineering, EEE, Civil Engineering, Chemical Engineering or Chemical Engineering (Plastics and Polymer), Mechanical Engineering or Biotechnology branches at BIT Mesra.
You may also try for other branches at our BIT Patna, BIT Deoghar and BIT Jaipur campuses.

Hi,
Visit this link to check colleges based upon your rank:
https://www.shiksha.com/b-tech/resources/jee-mains-college-predictor
Good Luck. Hope it helps.

I do not think there is any benefit of going for JoSAA counselling at this rank.

These amounts (35k or 75k) will get added to your semester's fee.