I have got 9.73 CGPA in class 12 of AP and Got 88.5% in jee mains 2019 (OC GEN). Can I get a CSE seat in Sastra University TN

Hello somanadh. You have a good 12th score and an decent JEE score. The criteria for SASTRA University is as follows
Through stream 1:

Admissions to 70% of the seats will be made through stream 1 on the basis of JEE Main scores and normalized scores of the 10+2 or equivalent exam.

The 25% weightage will be given to JEE Main scores and the remaining 75% will be given to marks scored in 10+2 or equivalent examination.

The combined scores will be used to prepare the rank list and candidates will be invited for admission on the basis of the rank list.

Through stream 2:

The remaining 30% of the seats will be filled through stream 2

Only 10+2 (or equivalent) normalized scores will be considered while preparing the rank list of stream 2.

Hope this helps.