Hello aspirant, it is difficult to predict you rank based on marks because the marks vs rank changes every year for Amrita University . Based on the number of students who take the exam, difficulty of question marks vs rank change drastically every year. But at this marks if you have given 12th from TN then you may get CS in Amrita University. The cut off for CS is generally under 6000 rank. Hope you understand.

BEST OF LUCK!!