This is a really bad idea, since it is going to take you off the security/bug fix update path. If you decide to do this, you'll have to purchase Extended Update Support in order to get supported security and bug fix updates. If at all possible, you should update to the latest minor version. (They are roughly comparable to Windows service packs.)
With that out of the way...
You may be able to use the create-release script to create a channel for a specific Red Hat release. However, this script doesn't seem to have been updated in a couple of years, so it may not work for RHEL 6.
Another option is to download the DVD for the specific release you want, and use it as a local yum repository.
Finally, you can call Red Hat and take advantage of that support you're paying insane amounts of money for.