Hello ; There is no particular cutoff in sastra university .It solely depends on your rank in sastra's merit list .Your marks/rank should be good enough that is better than all other applicants so that you can get admission.The admission is based on two ways :

1.Stream 1: JEE M marks + Board exam marks[70% seats]

2.Stream 2: Only Board exam marks [30% seats]

ALL THE BEST !!!!!