Dear candidate, In Sastra there is no minimum board cutoff or minimum percentile required in JEE. It is based on 12th percentage and jee main marks sastra will calculate like this:

12th percentage * 0.75+jee main mark * 0.25

It will be out of 165 marks. Then a merit list will be prepared. It is clearly visible that 75% percent marks are from boards and 25% marks of JEE. You need to have a good JEE score and high on boards. A minimum of 90+ marks in JEE and 95%+ marks in boards will keep you on a safer side. Chances are less. However, cutoff may vary due to some reasons:

Difficulty level of JEE

Number of candidates appeared in exam

Number of seats in college this time.

Hope, it helps!