I am providing you with the most basic information about student canteens, and for more information, contact the exchange coordinator you are communicating with or ask a question in a comment and I will do my best to find that information for you.
Names of student canteens:
Studentski Grad Restaurant
Tri Kostura Restaurant
Zemun (Žarko Marinović) Restaurant
Agronom Restaurant
Karaburma Restaurant
Patris Restaurant
Đušina Restaurant
Rifat Restaurant
Kralj Aleksandar Restaurant
Voždovac Restaurant
Mika Mitrović Restaurant
Farmaceut Restaurant
Košutnjak Restaurant
While the operating hours may vary, most canteens are open on weekdays as follows:
Breakfast: 07:00-09:00
Lunch: 11:00-15:00
Dinner: 17:30-20:30
Yes, what can be different but good here in Belgrade is that you can use your student card in any student canteen, so you are not tied to just one!
More info here.
Enjoy!