Shanmugha Arts, Science, Technology & Research Academy, known as SASTRA University, is a private university in the town of Thirumalaisamudram, Thanjavur district, Tamil Nadu, India. It was established in 1984 in the form of Shanmugha College of Engineering which is now renamed, Shanmugha Arts, Science, Technology & Research Academy [SASTRA]. The university offers undergraduate, postgraduate and research  courses in multiple streams such as Engineering, Science, Education, Management and Arts. 

SASTRA university admissions is based on the marks obtained in the last qualifying examination. In case of B.Tech, M.Tech and Law courses, scores obtained in national level examinations such as JEE Mains, GATE and CLAT respectively, are also considered for admission.

B.Tech: JEE Main+ 10+2 merit (for 70% seats) and 10+2 merit (for 30% seats)

So solely JEE mains doesn't matter you need your 10+2 marks too to qualify for SASTRA university and CSE being most demanded branch of SASTRA University you need to be among the one on the top of there rank list.