Hi Ezhil,

1) In TNEA counselling the seats are first filled in the open category, There are chances that the candidates might have got the seat allocated in general category. Also the the total allocation for SCA category is around 3% of the total colleges under anna university.

2) The cutoff rank for ST is lower compared to other categories, the candidate would have opted for other courses (preferably a circuit branch) since the courses you have mentioned required lower cutoff ranks even for the open category.

The common fact is that the rate of engineering admissions have decreased in 2019 compared to the previous years, this can be even one of the reasons the seats weren't filled.