https://developer.nvidia.com/nccl/nccl-download Download deb file

Install the repository
For the local NCCL repository:sudo dpkg -i nccl-repo-<version>.deb

Update the APT database:sudo apt update

Use APT to install libnccl2. In addition, if you need to use NCCL to compile the application, install the libnccl-dev package at the same time.
sudo apt install libnccl2=2.9.6-1+cuda10.2 libnccl-dev=2.9.6-1+cuda10.2