What is the prefix for located?

There isn't a specific prefix for "located". "Locate" itself is the verb form. However, you can use prefixes like "re-" or "mis-" to modify its meaning:

* Relocate: To move to a new location.

* Mislocated: To place in the wrong location.

If you're looking for words that indicate location, you might use prefixes like "geo-" (relating to the earth) or "topo-" (relating to place).