70 percentage of seats in Sastra University are filled through the boards (weightage 75%) + jee mains(weightage 25%) both consideration itself.

So your boards percentage are approximately 93-94%.

So 94*100/98 = 95.91 (Assuming toppers percentage to be 98)

Now 95.91 * 0.75 + 89 * 0.25 = 94.18

So this is your final score.

So at this score hopefully you can make through and get a seat.

Refer to the site below for more detailed information...

https://engineering.careers360.com/articles/sastra-btech-admission

Best wishes. Thank you.