IISc Bangalore does not grant admission solely to highly intelligent people. Rather, IISc Bangalore makes people highly intelligent. I say this out of my personal experience.
When I entered IISc Bangalore, I knew I was not highly intelligent. I was, however, deeply inclined toward learning and research.
My interview for IISc Bangalore ran for around two hours. The interview began with-
“Plot y=k exp(cx) for different values of k and c (positive, negative, and combination)”, and it ended in my M.Tech thesis. I tried to derive all the values and answer all the questions. Whenever I got stuck, the faculty members helped me conclude.
At IISc Bangalore, you will become more and more inclined towards learning. You will understand yourself and your goals. Then, how people label you won’t be of any importance to you.