@qqdev: those in-game X-/Y-Coordinates are calculated through RegionID (X-/Y-Sector) and X-/Y-Offsets
_RefRegion contains information about a region safezone or not (isBattleField).
So you can pick a region randomly and again X,Y,Z offsets (0-1920) but you get a pretty high chance of landing right within an object. Navmesh could help you here but can get your solution complex really quickly.
The easiest approach that comes to my mind when searching for safe positions across the whole map are spawn positions for monsters. Tab_RefNest contains ~16563 positions that I assume to be not within an object. npcpos.txt might work as well.