hwo install on centos6 openvpn?

http://mirror.centos.org/centos/6/cr/x86_64/repodata/repomd.xml: [Errno 14] PYCURL ERROR 22 - «The requested URL returned error: 404 Not Found»
Trying other mirror.
To address this issue please refer to the below wiki article

https://wiki.centos.org/yum-errors

If above article doesn't help to resolve this issue please use https://bugs.centos.org/.

Error: Cannot retrieve repository metadata (repomd.xml) for repository: cr. Please verify its path and try again



CentOS-CR.repo

[cr]
name=CentOS-$releasever - CR
baseurl=http://mirror.centos.org/centos/$releasever/cr/$basearch/
gpgcheck=1
enabled=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-6

Hi, CentOS 6 is too old and some mirrors do not work anymore. Try to check the link of the mirror you use: http://mirror.centos.org/centos/6/readme
I would suggest to find another mirror