Not totally sure about RHEL but I bet we can get it figured out.
When you run nvcc —version does it fail?
RHEL packages appear to be publicly available without any sort of restrictions
https://developer.download.nvidia.com/compute/cuda/repos/rhel8/x86_64/cuda-rhel8.repo
https://developer.download.nvidia.com/compute/cuda/repos/rhel9/x86_64/cuda-rhel9.repo