Torch.cuda.is_available() returns False

Hi @gabrielmurilocicotoste6, please install one of the PyTorch wheels from this topic that were compiled for JetPack 4 and CUDA 10.2:

You probably will have to revert the changes you made with CUDA 11.8 back to 10.2, because not only is CUDA 11 not supported on JetPack 4 (note that the Ubuntu package version for what you installed was 20.04, while JetPack 4 is on 18.04), but the PyTorch wheels for JetPack 4 were also built against 10.2 and you would get a similar error if you tried running PyTorch wheels built against a different major version of CUDA.