I have CAT 83, 10th-78%,12th-78%,graduation B.E -65%.what are my chances of getting into the college?

I am sorry that you might not get call from the college. For further clarification please look at the following link to get clear picture about your status. http://www.iimshillong.in/admission/Admission Process 2016.pdf

Hello, For engineering background, at 83 percentile, it is unlikely that will get a call. However, you have not mentioned your caste. The CAT cut-offs vary for different castes so that is another aspect to consider.

Sorry to inform you but in my view chances are very slim.

Chances are not great as CAT percentile is a bit low. If you get a GD PI call you would have to perform really well.

I can't say for sure because cutoffs keeps changing every year, but going by past trends you might be on border.