Sastra University has no cutoff specified for different branches or colleges. They intake candidates based on their intermediate and JEE Main marks.
To get a secure position into the college then rank should be below 700. You can try for the different colleges affiliated under Sastra University and wait until the further round results. Put options such that you will get a college for sure. Keep a security option always.
You can get an admission into the college but getting CSE branch may not be possible. Still keep on trying for other colleges for CSE branch.
Hope it helps!