CUDA Runtime version Vs CUDA Driver version

CUDA Driver Version: 11.0
CUDA runtime version: 10.1.243

I found CUDA driver version using nvidia-smi command is 11.0. Depending on this version I installed compatible PyTorch using the command conda install pytorch==1.7.1 torchvision==0.8.2 torchaudio==0.7.2 cudatoolkit=11.0 -c pytorch. Now, if I run the command torch.cuda.is_available() to check the availability of CUDA it returns False.

I also ran the command !python -m torch.utils.collect_env to collect the environment information which returned:

Collecting environment information...
/home/user/anaconda3/envs/tf-gpu/lib/python3.6/site-packages/torch/cuda/ 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
PyTorch version: 1.7.1
Is debug build: False
CUDA used to build PyTorch: 11.0
ROCM used to build PyTorch: N/A

OS: Ubuntu 20.04.1 LTS (x86_64)
GCC version: (Ubuntu 9.4.0-1ubuntu1~20.04.2) 9.4.0
Clang version: Could not collect
CMake version: version 3.16.3

Python version: 3.6 (64-bit runtime)
Is CUDA available: False
CUDA runtime version: 10.1.243
GPU models and configuration: GPU 0: GeForce RTX 2070 SUPER
Nvidia driver version: 450.119.03
cuDNN version: Could not collect
HIP runtime version: N/A
MIOpen runtime version: N/A

Versions of relevant libraries:
[pip3] numpy==1.19.2
[pip3] torch==1.7.1
[pip3] torchaudio==0.7.0a0+a853dff
[pip3] torchvision==0.8.2
[conda] blas                      1.0                         mkl  
[conda] cudatoolkit               11.0.221             h6bb024c_0  
[conda] mkl                       2020.2                      256  
[conda] mkl-service               2.3.0            py36he8ac12f_0  
[conda] mkl_fft                   1.3.0            py36h54f3939_0  
[conda] mkl_random                1.1.1            py36h0573a6f_0  
[conda] numpy                     1.19.2           py36h54aff64_0  
[conda] numpy-base                1.19.2           py36hfa32c7d_0  
[conda] pytorch                   1.7.1           py3.6_cuda11.0.221_cudnn8.0.5_0    pytorch
[conda] torchaudio                0.7.2                      py36    pytorch
[conda] torchvision               0.8.2                py36_cu110    pytorch

I would like to know which PyTorch version I need to install in the conda environment to access the CUDA? Is it depending on CUDA runtime version(10.1.243) or CUDA driver version (11.0)?

Thank you.