Sounds like it was originally built as a ULN system
https://docs.oracle.com/cd/E37670_01..._regu_uln.html ie its the Oracle (non-free) rebuild of RHEL.
You need to a) check the history of the system and the settings, then b) decide which company you want to pay for updates & support and convert as necessary.
Note that although you might(!) be able to force a system to switch/merge from one to the other, a) stability would be an issue and b) if you ever raise a support ticket, they'll both insist on a 'supported setup' which means a clean install, not a Frankenstein one...
HTH