How to get mod_proxy_fcgi on CentOS/Red Hat 6 with Apache 2.2?
mod_proxy_fcgi needs Apache 2.3 and later, which is why you get it packaged with Apache 2.4 and not with 2.2.
For the Ceph project we needed to backport mod_proxy_fcgi to httpd 2.2 on RHEL 6, and I've put this package in EPEL. Enable EPEL, then "yum install mod_proxy_fcgi"