For Stream 2:
Candidates will be considered for admission based on their normalised aggregate 10+2 or any equivalent exam scores.
30% of seats will be filled under stream 2.
By this we can say that If you will get good JEE main rank then only you'll be eligible to enter into Sastra. 
Generally it requires a cut off of 98% or 980 normalised score.

The closing rank for round one was around 700 for different seats as per previous years.So chances are there.

Visit this for more details on admission procedure.

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

Thanks.