Hello,

Central seat allocation board conducts the CSAB special round for  NITs, IIITs and GFTIs.
Two special round are conducted after the conclusion of all the rounds of JOSAA counselling to fill in the vacant seats.
Those Candidates who were not allotted any seats throughout the counseling or wish to upgrade their previous alotted seats can participate in the CSAB special rounds.
You can refer to the following article to know more about CSAB and the cut-off for previous years

https://engineering.careers360.com/articles/csab-special-round-for-nits-iiits-and-gftis