Man, you are in first year and not even fully done with first semester. Worry about these things after the sixth semester. Planning is good, but, if you always keep on planning, when will you experience what life has to offer? You have not even entered IIT, you are thinking about Ph.D. Then, when you enter Ph.D., there will be planning for job or post-doc.
I am sorry to disappoint, but in my first year, a job or Ph.D. was the last thing on my mind. Good luck with your studies.
Edit: I thought he was a B.Tech. student in first year, hence this answer. Sorry.