Hello Applicant

There are several common entrance test conducted by different state as an Entrance exam into different courses, now since you have not mentioned the specific CET you are talking about feel free to mention it in the common. Although the general factors which determine the seat allotment are:

The number of students appeared in the exam

the difficulty level of the exam

the seat matrix

Now since you are from St category you still have some chances to make it through but with some possibilities to stay in the waited list.

Hope it helps!!!