I have installed cuda-9-2 but after installation once I run nvidia-smi it is showing cuda 11. Please check below screenshot. I have verified cuda-9-2 in /usr/local and its present there. Also, nvcc is confirming the same.
/usr/local/cuda-9.2/bin/nvcc --version
nvcc: NVIDIA (R) Cuda compiler driver
Copyright (c) 2005-2018 NVIDIA Corporation
Built on Tue_Jun_12_23:07:04_CDT_2018
Cuda compilation tools, release 9.2, V9.2.148
Nobody is suggesting you have more than one CUDA installed and the answer there does not assume that.
You have a GPU driver installed that supports driver API activity up through CUDA 11.4
You have a CUDA toolkit installed that supports CUDA 9.2.
The answer on SO explains how that is possible. And why it is probably OK.
In any event, I don’t see that you have asked a question here or on SO.
It is simply a fact that nvidia-smi can show a “different CUDA version” from the one that is reported by nvcc. They are reporting two different things.