No package python-twisted available.
But I wonder if that is a result of this:
This system is not registered with RHN.
RHN support will be disabled.
Does that mean you stopped paying for support? Or is something misconfigured?
The python-twisted package (spelled just like that) is in Fedora repositories. I would be surprised if it's not in Redhat.
If you are choosing to no longer pay for updates, I would recommend switching to Fedora. Redhat is supposed to be super stable, but I have no problems with Fedora.