What entitlement is required to access the MRG Realtime channels?

Issue

• What subscription is required to access the channel "MRG Realtime v. 2 (for RHEL 6 Server x86_64)"?

• Yum install fails with the following message:

# yum groupinstall "MRG Realtime"
[...]
[Errno -2] Name or service not known
Setting up Group Process
Warning: Group MRG Realtime does not exist.
No packages in any requested group available to install or update