I have been allotted a test centre in Hyderabad while I live in Pune, what should I do in this case ? I feel very demotivated now.

Go to Hyderabad bro. At least you'll get good biryani! Also all the best

See brother, These are external factors that you cant control.(there going to be lot more surprises like this in your life ahead). I assume you have prepared diligently for a year. Dont let this things dictate terms. Just put a smile on your face. Book a hotel room.,Checkin previous day. Rest well. Do well in CAT and show yourself that Centre and all cant hold you back from getting to IIM. Dont Forget to try Biryani :) Only After Exam btw.

Bro idk why i filled my test center in my home town in Jharkhand and currently i am in Delhi NCR so i have to travel approx 1300 km to give my cat exam. After that i have to return before 29th coz my university exams will start. So dont worry see this positively and crack the cat with good percentile. It will all worth in the end.