CS in CUSAT is the 2nd most sought out subject after Naval Architecture. In the CUSAT entrance exam the first few seats are filled in the Naval Architecture branch then the CS seats. In all the branches first, the seats are filled in the main campus and then in the second campus.
According to the previous year’s report, the required cutoff for CS in the first round was 740. While in the third round the cutoff was 1037. Going by the cutoff trends, I will say you have a good chance of getting CS on the main campus.