This depends on your preference.
Do you want to rent a flat? Or need a residence type accommodation?
METU has good dormitories. This must be your first option.
Secondly, you can rent a flat at 100. YIL. 100. YIL is next to METU just at its back gate.
Around 100. YIL, you can rent flats at Cigdem, Karakusunlar, Cukurambar (expensive).
The best transportation is from 100. YIL since it is 10 minutes walking to the dorm district of METU.
Also as an alternative, you can find students looking for flatmates. These ads generally on the ad boards of the dormitories.
Ankara, but specifically around METU is a bit expensive in terms of rent. A flat will cost you min. around $500.
You can contact me for specific details and questions. I am living in Ankara and also am a graduate of METU. almost 8 years ago