About c# : how-do-I-setup-the-dot-net-6-sdk-on-my-operating-system

I’ve downloaded dotnet6 sdk on my ubuntu-mate 21.10 and it works. the tar.gz contents are:

host
LICENSE.txt
metadata
packs
sdk
sdk-manifests
shared
templates
ThirdPartyNotices.txt

where and how do I move my files and folders to the correct destination so that they would and be in PATH for development, and have runtimes in PATH so I can run my compiled applications. without getting runtime missing error

first you to this link
then scroll down to 21.10 (if you’re on version 21.10) and run these commands with bash:

wget https://packages.microsoft.com/config/ubuntu/21.04/packages-microsoft-prod.deb -O packages-microsoft-prod.deb
sudo dpkg -i packages-microsoft-prod.deb
rm packages-microsoft-prod.deb

Note

The .NET 6 packages haven't yet been published for Ubuntu 21.10. 
The following wget command uses the Ubuntu 21.04 repository.
This article will be updated when the packages are available in the Ubuntu 21.10 repository.

then scroll down to install the sdk section and copy and run these commands:

sudo apt-get update; \
  sudo apt-get install -y apt-transport-https && \
  sudo apt-get update && \
  sudo apt-get install -y aspnetcore-runtime-6.0

if you only want the runtimes then run these commands instead:

sudo apt-get update; \
  sudo apt-get install -y apt-transport-https && \
  sudo apt-get update && \
  sudo apt-get install -y aspnetcore-runtime-6.0