Qatar Airways has got very good offer for flights from Belgrade to Asia on Business Class. You can fly from 1036 Euro return!! Found prices are for travel now until the end of November (however July – September flights are very limited). For booking go to IWTF or momondo. However Qatar Airways website is running simultaneously other special. If you book directly via Qatar website you will earn double Qmiles. So your choice. Cheaper option or more Qmiles. Book by July 19th.
Example of bookings from Belgrade (Business Class):
And many more (check on Qatar Airways website Asian Destinations).
Before you book check reviews on TripAdviser