Hey Karthick

Yes, indeed there are cut off ranks for all the rounds of JoSAA counselling. The cut off ranks change acccordingly as the number of students taking part in the counselling process changes. For every succeding round, the closing ranks go a bit lower than what it was in the previous round as the vacancy is created in any particular branch. That means, that possibility of getting a desired branch increases round by round. To know more, you can check the previous years cut offs for all the 7 rounds.

I hope this helps. 

Regards.