Hello, 

There might be a chance for you to get NITs through CSAB rounds but expecting a very good NIT is a bit far fetched. The best chance for you will be in NorthEastern NITs only where there are considerable amount of seats left. Home NIT for keralite in Calicut and it has 2-3 seats left in each branch (I would recommend you to see the seat matrix yourself also). Thus NIT Calicut should be your top choice and best practical option you can get. Otherwise you can get some core branch or maybe even CS or ECE in North eastern NITs like Silcher and Agartala. You should definitely go for the CSAB rounds. All the best.

Thank you

Hello,
The Central Seat Allocation Board (CSAB) special round is for admission of all JEE Main 2019 qualified candidates in left over seats of NITs,IIITs and SFTIs after the initial rounds of counselling.
With 19k OBC category rank your chances of getting a decent government engineering college are very high.
So, rest assured and be updated with the counselling dates etc.
Follow this link for more
https://www.google.com/amp/s/engineering.careers360.com/articles/csab-special-round-for-nits-iiits-and-gftis/amp
Good luck