[A2A] Other than what Prof. Dheeraj Sanghi and Shanmuganathan Raman wrote, I would recommend every applicant to do some teaching during their Ph.D. You can request your adviser to allow you to teach a few lectures or tutorials, so that you know that if you like teaching and are reasonably good in it. If teaching interests you, then even if you are not good in the beginning, it will slowly improve with practice. If teaching does not interest you, an institution like IIT is not a good place to be. It is better to be in a more research oriented institute like IISc or TIFR. If you come to IITs with almost no interest in teaching, it would not be a fulfilling experience for either you or your students.