This is a great question, and we've got a great answer for it! You just have to wait a short while.
Red Hat is just about to release .NET Core packaged for RHEL. Along with the binary bits there is some brand-new documentation that outlines the very short list of steps necessary to install .NET on RHEL. (It's super easy!)
Stay tuned, and watch RHEL's 'Software Collections'. It won't be long!