Did you see the following ->
Oracle Linux/Red Hat Enterprise Linux (RHEL) versions 4 and 5 and SLES versions 9 and 10 were previously certified with 12.1 but are no longer actively supported by the vendors.
--Ref: R12.1.1 : Oracle E-Business Suite Installation and Upgrade Notes Release 12 (12.1.1) for Linux x86 (Doc ID 761564.1)
Why don't you just use Oracle Linux 6? --- repo ->
https://yum.oracle.com/oracle-linux-6.htmlFor Oracle Linux 5 packages see ->
https://yum.oracle.com/oracle-linux-5.html & if you still can't find your package, just check the RPM sites which are publically available on internet.