Installing cuda libraray on ubuntu 20.4 getting error

I am trying to install cuda toolkit for deep learning /machine learning using the following command on ubuntu 20.04 version using the following command
sudo apt install nvidia-cuda-toolkit
but I am getting the following error. Please help and support:

Err:69 http://in.archive.ubuntu.com/ubuntu focal/multiverse amd64 nvidia-cuda-gdb amd64 10.1.243-3
Unable to connect to in.archive.ubuntu.com:http: [IP: 43.255.166.254 80]
Err:70 http://in.archive.ubuntu.com/ubuntu focal/multiverse amd64 nvidia-profiler amd64 10.1.243-3
Unable to connect to in.archive.ubuntu.com:http: [IP: 43.255.166.254 80]
Ign:71 http://in.archive.ubuntu.com/ubuntu focal/main amd64 opencl-c-headers all 2.2~2019.08.06-g0d5f18c-1
Err:72 http://in.archive.ubuntu.com/ubuntu focal/main amd64 ocl-icd-opencl-dev amd64 2.2.11-1ubuntu1
Unable to connect to in.archive.ubuntu.com:http: [IP: 43.255.166.254 80]
Err:73 http://in.archive.ubuntu.com/ubuntu focal/multiverse amd64 nvidia-opencl-dev amd64 10.1.243-3
Unable to connect to in.archive.ubuntu.com:http: [IP: 43.255.166.254 80]
Err:74 http://in.archive.ubuntu.com/ubuntu focal/multiverse amd64 nvidia-cuda-toolkit amd64 10.1.243-3
Unable to connect to in.archive.ubuntu.com:http: [IP: 43.255.166.254 80]
Err:75 http://in.archive.ubuntu.com/ubuntu focal/multiverse amd64 nvidia-visual-profiler amd64 10.1.243-3
Unable to connect to in.archive.ubuntu.com:http: [IP: 43.255.166.254 80]
Err:68 http://in.archive.ubuntu.com/ubuntu focal/multiverse amd64 nvidia-cuda-doc all 10.1.243-3
Could not connect to in.archive.ubuntu.com:80 (43.255.166.254), connection timed out [IP: 43.255.166.254 80]
Err:71 http://in.archive.ubuntu.com/ubuntu focal/main amd64 opencl-c-headers all 2.2~2019.08.06-g0d5f18c-1
Unable to connect to in.archive.ubuntu.com:http: [IP: 43.255.166.254 80]
Fetched 905 MB in 2min 53s (5,216 kB/s)
E: Failed to fetch http://in.archive.ubuntu.com/ubuntu/pool/multiverse/n/nvidia-cuda-toolkit/nvidia-cuda-doc_10.1.243-3_all.deb Could not connect to in.archive.ubuntu.com:80 (43.255.166.254), connection timed out [IP: 43.255.166.254 80]
E: Failed to fetch http://in.archive.ubuntu.com/ubuntu/pool/multiverse/n/nvidia-cuda-toolkit/nvidia-cuda-gdb_10.1.243-3_amd64.deb Unable to connect to in.archive.ubuntu.com:http: [IP: 43.255.166.254 80]
E: Failed to fetch http://in.archive.ubuntu.com/ubuntu/pool/multiverse/n/nvidia-cuda-toolkit/nvidia-profiler_10.1.243-3_amd64.deb Unable to connect to in.archive.ubuntu.com:http: [IP: 43.255.166.254 80]
E: Failed to fetch http://in.archive.ubuntu.com/ubuntu/pool/main/k/khronos-opencl-headers/opencl-c-headers_2.2~2019.08.06-g0d5f18c-1_all.deb Unable to connect to in.archive.ubuntu.com:http: [IP: 43.255.166.254 80]
E: Failed to fetch http://in.archive.ubuntu.com/ubuntu/pool/main/o/ocl-icd/ocl-icd-opencl-dev_2.2.11-1ubuntu1_amd64.deb Unable to connect to in.archive.ubuntu.com:http: [IP: 43.255.166.254 80]
E: Failed to fetch http://in.archive.ubuntu.com/ubuntu/pool/multiverse/n/nvidia-cuda-toolkit/nvidia-opencl-dev_10.1.243-3_amd64.deb Unable to connect to in.archive.ubuntu.com:http: [IP: 43.255.166.254 80]
E: Failed to fetch http://in.archive.ubuntu.com/ubuntu/pool/multiverse/n/nvidia-cuda-toolkit/nvidia-cuda-toolkit_10.1.243-3_amd64.deb Unable to connect to in.archive.ubuntu.com:http: [IP: 43.255.166.254 80]
E: Failed to fetch http://in.archive.ubuntu.com/ubuntu/pool/multiverse/n/nvidia-cuda-toolkit/nvidia-visual-profiler_10.1.243-3_amd64.deb Unable to connect to in.archive.ubuntu.com:http: [IP: 43.255.166.254 80]
E: Unable to fetch some archives, maybe run apt-get update or try with --fix-missing?

After this error not able to enable the CUDA for deep learning. Please help here

can anybody help me on this?

Hi, this would be the correct forum for this question: CUDA - NVIDIA Developer Forums