If we talk about counselling, there are various types of counselling where various types of institute do participate.

And to get admission into NITs, IIITs, IITs, GFTIs, you need to participate under JoSAA counselling..
Where as CSAB counselling is being conducted for left over seats of institutes which comes under JoSAA Counselling and this counselling will be conducted once the JoSAA Counselling is done.

Also you can check your chances in detail by our college predictor: