Logon to
redhat support using the support ID provided while buying the license.
re-generate a key for your machine from the available options in the support site and register you machine to the redhat support site.
use rhn_register command to register your server machine with the key. before that ensure that your machine is able to reach the internet.
Now you can refresh the support website and you can able to see your machine got registered.
Best regards,
