Cuda is not available

Pytorch version: 1.7.1
Cuda version : 11.0

import torch
torch.cuda.is_available() returns false

The error message : python3.6/site-packages/torch/cuda/init.py:52: UserWarning: CUDA initialization: CUDA unknown error - this may be due to an incorrectly set up environment, e.g. changing env variable CUDA_VISIBLE_DEVICES after program start. Setting the available devices to be zero. (Triggered internally at /opt/conda/conda-bld/pytorch_1607370120218/work/c10/cuda/CUDAFunctions.cpp:100.)
return torch._C._cuda_getDeviceCount() > 0

This issues is usually because of Cuda torch incompatibility.
Can you please check and try a fresh setup?

Thanks