Hi,

• In CSAB counselling irrespective of the category, it is CRL rank which is considered.
• Difference is just that CSAB is for filling the Vacant seats. In CSAB you get less time for reporting.

In CSAB Special Rounds the vacant home state seats are converted into all india quota seats, i.e the seats become open to all. Here, in CSAB rounds the CRL Rank is considered rathar than that of Category Rank.

However, the reservation seats are to be filled up by the reserved candidates and not by General/UR. The Rank may go very below for SC/ST/OBC candidates than that of UR candidates.

Use this link to get more information about CSAB -

https://engineering.careers360.com/articles/csab

Hope this helps.

Good luck.