Register

subscription-manager register --username MYRHLOGIN --password MYRHPWD --auto-attach

Subscription

List all available subscriptions :

subscription-manager list

Subscribe :

subscription-manager subscribe --auto

Change distibution version

You can set your preferred release level using the subscription-manager tool. Example to set release to version 6.4 :

subscription-manager release --set=6.4
yum clean metadata all
yum downgrade redhat-release
yum distro-sync

Check redhat version

using command lsb_release

First, install package redhat-lsb-core:

yum install redhat-lsb-core

Now, you can check the version:

/usr/bin/lsb_release -a

using file /etc/redhat-release

cat /etc/redhat-release

using file /etc/issue

cat /etc/issue