Hello Aspirant.

As you've mentioned that you've scored 83 percentile in JEE main examination and assuming that you are a general category candidate. Then according to the formula

Rank=(100-perventile)*8690.10

Your rank is around 1,47,730-1,47,750. At this you might not get admission into amrita University.

Amrita University conducts its own examination "AEEE". If you're able to score good in it, then you might get admission into that University.

Best of luck !