With 974 marks in your intermediate exams and 83 percentile in JEE Mains, you have a good chance to get admission in SASTRA University. SASTRA considers both board marks and JEE scores for admission. Your excellent board marks will help a lot, even if your JEE percentile is moderate. You can apply through their admission process based on board performance or JEE rank. So yes, you can expect a seat in SASTRA, especially in branches like engineering or related fields.