Looking for rpm's for RHEL 5.5

I am looking for the rpm's to install the following software on a RHEL 5.5 platform. I would like to install these from a redhat channel if possible. One thing I noticed is some of this software and the versions I need are in the RHEL 6 channels. Can I install these packages listed under a RHEL 6 channel on a RHEL 5.5 server?

Here's the software:

Ruby 1.8.7

RubyGems 1.3.7

Subversion 1.6

mysql 5.5

git 1.7

nginx 0.9 or 1.0

Thanks in advance for any help you can provide,

Mark