The PyTorch binaries ship with a statically linked NCCL using the NCCL submodule 2. The current CUDA11.3 nightly binary uses NCCL 2.10.3 already, so you could use it.
On the other hand, if you want to use a specific NCCL version, which isn’t shipped in a binary release, you could build from source and use your locally installed NCCL via:
NCCL_INCLUDE_DIR="/usr/include/" \
    NCCL_LIB_DIR="/usr/lib/" \
    USE_SYSTEM_NCCL=1 \
    python setup.py install