Can I take part in 2nd round if I had taken admission after 1st round in bit sindri????
If you have already taken admission in BIT Sindri then they won't consider you for the second round of counselling. For that they'll ask you to first withdraw the admission as you would have already paid the admission fees during your admission. That would become a little risky but if you're dissatisfied with the branch you're getting you can definitely do so.
Good luck