Looking on the wiki a Hylotl Ruined Castle can appear on any planet with the exception for moons, any ocean worlds (including magma, arctic, and toxic) or garden planets.
I like Hylotl Ruined Castles because they have that Japanese feel to them but while in my current game i made my base from one, the problem is that this one was in the starting solar system so it wasn't hard for me to find and i fear that if i start a new game i wont find another one so easily.
So is there a way to force a Hylotl Ruined Castle to appear on a planet?