chances of getting in

My gre score in first attempt is 310( Q=164, V=146, AWA=2.5) and for 2nd attempt my score= 308(Q=165, V=143, AWA=3) with cgpa=7.18/10. What are my chances of getting power electronics in iit Chicago?

I take it you are interested in a Masters degree. If you look at the exam requirements, you are OK for the total score and the Q part but a bit low on the AWA (3.5 is the posted minimum). If you are an international applicant, you also need a strong TOEFL. My guess is that you will have a chance of being reviewed seriously. I cannot say what the chances are, the ECE department has a lot of applicants.

i am an international applicant and my toefl score is 97

That is good and certainly meets our minimum.