Hello Kalyana,

There are very fewer chances that seats will remain vacant after 7 rounds of counseling. Seats in some low ranked branches might be vacant. You have not mentioned any college for which you want to check the closing rank. So, The closing ranks for Mechanical Branch for the given colleges are -

IIT, Bhubaneswar - 6183

IIT, Bombay - 999

IIT, Mandi - 7222

IIT, Delhi - 1222

You can check the closing rank of other IITs from the link given below -

https://josaa.nic.in/webinfocms/Handler/FileHandler.ashx?i=File&ii=177&iii=Y

All The Best.