I got 975 marks in inter and in mains I got 82 percentile . is there any chance of getting a seat in sastra main campus?? also is there any chance of getting cse branch in sastra University??

Greetings of the day Uday

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.
I would recommend you to apply for SASTRA without any fear as I see a little possibility that you may get a seat there.

Hope this clears all your doubts!!

All the best for your future endeavours