CUDA toolKit and Drivers problem-reg

I have installed CUDA 11.0 version and later downgraded to CUDA 10.1. the command
nvcc --version
shows version 10.1, but when i run the command
it shows CUDA version to be 11.0.
Inorder to enable GPU usage(Quadro P620), i need to use CUDA 10.1 version for GROMACS to solve the compatibility issues. How can i uninstall the drivers and reinstall the appropriate one. I tried

  1. sudo /usr/bin/nvidia-uninstall
    sudo: /usr/bin/nvidia-uninstall: command not found

let me know, how can i solve the issue