MİUS is subsonic (0.8-0.9 mach) UCAV, Göksungur is supersonic (1+ mach, probably 2+ mach) UCAV. Göksungur for air-to-air combat, MİUS for aerial to ground bombing purposes.
You can think of MİUS as the drone to replace the F-4 Phantom II, and Göksungur as the drone to replace the F-16 Fighting...