Your GTX 860M would have a compute capability of 5.0 and would thus work with the PyTorch binaries.
Make sure you have the appropriate NVIDIA driver for the CUDA version you are selecting from the installation page 10. You can find the required NVIDIA driver for each CUDA version here 5 in Table1.
Note that you don’t need a local CUDA toolkit installation, as the conda binaries and pip wheels will ship with their CUDA (cudnn, NCCL, etc.) runtimes.
You would need the local CUDA toolkit, if you are planning to build PyTorch from source or compile any custom CUDA extensions or 3rd party libs.