Quetz usually spawn at red obelisk, if you don't see one wait a few minutes for t to spawn. If you are looking for a high level kill the lower level one so it another can respawn

It u have a base at red obi dont wait for it i waited 9 hours before it hot killed by a giga at blue im pissed i have 1 hour left before war and ima gona die

For 'The Center' map the common spawn locations tend to be near any obelisk, as well as around 55,45 or cruising around the entirety of Jungle South. It's worth checking around lava island too.

Low levels seem to spawn neared red obbi on the island. If you're looking for one, head over there