[CentOS] CentOS 6.3 packages updates options without upgrading.

Hi,
IT seems, centos6.3 does no longer get any updates esp security fixes as
per readme here:
http://mirror.centos.org/centos/6.3/readme

Is there updated source RPMs that can be rebuilt and hand patched, for
example, nss-util 3.21.0-2 or openssl 1.0.1e that can be safely used on
CentOS 6.3? Any other options that you can shed some light on, highly
appreciated for above examples.  My apologies if this is not the right
group to post such questions or if any existing literature available for
same, please kindly refer to right place.

The other option is to use CentOS 6.8 updated package on 6.3, but I am not
sure of any upstream and downstream dependencies in 6.3 without updating
the rest of the userland from 6.3 to 6.8.  Nonetheless, would this option
be feasible?

Appreciated very much, Thank you.