It should be listed under oracle. (If not, ask the sysadmin, who should always know what's on the box). If it is there, you should get back a single location. Otherwise, you'll get back something like:
no oracle in /usr/bin /usr/local/bin /......
and it will list all the directories in your $PATH.
Well, since Oracle's a product from Oracle Corporation, not Sun Microsystems and about the cheapest version I know of for business server use runs about $16K/cpu, statistically, it's not likely that the box has Oracle on it.
Usually the Oracle stuff will be in a directory named /OraHome or at least /Ora-something.
However, Oracle is a database server. Just because Oracle's not on that box doesn't mean that some other machine in the network isn't running Oracle. In which case that machine would still have Oracle available to it.
Sometimes the only way things ever got fixed is because people became uncomfortable.