Hello, Currently I am missng subscription for 'RHEL 5 Extended Life Cycle Support'. Can we patch RHEL 5.x with Oracle Enterprise Linux 5.x repo to avoid the security vulnerabilities.
In the past I have used both CentOS and Oracle Linux repo's for Redhat.
(keep in mind Oracle Linux 5 support ends June 2020) so at best you gain 6 months.
Sooner or later you will have to upgrade to 6, or preferably 7 or 8.