Thanjavur

The admission in SASTRA University is based upon two streams:
Stream 1: 75% marks of class 12 boards and 25% marks of JEE Mains is considered for ranking.
70% of the seats get filled with this stream. As your percentile I'm JEE Mains is less, your rank will get increased. If your class 12th percentage is around 90-95% and 80% in JEE Mains, then you have good chances to get into SASTRA University.
Stream 2: Your rank is calculated based upon your class 12 percentage only.
30% seats get filled with this stream. Since the number of seats is less will this stream, the competition is very high. To get into SASTRA through this stream, you need more than 95% in your class 12th boards. As your percentage in class 12 boards as well as in JEE Mains 2021 are good, so you have good chances to get into CSE branch from SASTRA University.

Sastra University, located in Thanjavur, Tamil Nadu, India, is known for its academic excellence in various fields of study. The university has been accredited with an 'A' grade by the National Assessment and Accreditation Council (NAAC) and has been ranked as one of the top universities in India by various agencies. Sastra University has a strong focus on research and innovation, and its faculty members are highly qualified and experienced. The university has collaborations with leading universities and research institutions around the world, which provides students with a unique opportunity to gain exposure to different cultures and research methodologies. The university offers undergraduate, postgraduate, and doctoral programs in various fields, including engineering, Science, management, law, humanities, and arts. The curriculum is designed to provide students with a broad-based education that prepares them for successful careers in their chosen field. Overall, Sastra University is a well-regarded institution of higher learning that provides students with a quality education and opportunities for personal and professional growth.

There is no such criteria (minimum JEE marks) for admission in to SASTRA university. SASTRA university has a separate procedure through stream 1 and stream 2 .
Stream 1
70 percent seats of every branch are filled through stream 1 based on 12 th percentage ( 75 percent after normalisation ) + JEE mains score ( 25 percent )
For example
12 th percentage - 88 (CBSE) and JEE mains score is 80 .
Normalised percentage of board would be as follows
88 * 100/98.6 = 89.25
(Assuming percentage of topper is 98.6 )
Now 89.25 * 0.75 + 80 * 0.25 =86.94
This is your final score . AIR (SASTRA) is prepared based on this final score . There is a chance AIR up to 4000 .
If someone is a topper of board exam and his JEE mains score is 40 then final score would be 85 and AIR (SASTRA) would be above 5000 . It proves that there is no chance for JEE mains score below 40 in stream 1 .
Stream 2 .
30 percent seats of every branch are filled through stream 2 based on 12 th percentage .
There is very less chance for percentage below 95 in stream 2 .
I know your chances are less but your intermediate marks is good so you still stand a chance to get admission through stream 1.