Unfortunately, there is no standalone installer for RSAT (Remote Server Administration Tools) available for Windows 11. Microsoft only provides the RSAT download version for Windows 10. In Windows 11, RSAT tools are integrated into the "optional features" section inside the Settings app.
Here are the steps to install RSAT tools on Windows 11:
Press the Windows key + i to open the Settings app.
Click System.
Scroll down and click "Optional features".
Click "View features".
The "Add an optional feature" window will now open. Search for "RSAT".
Select the RSAT tools that you want to install and click Next.
Confirm the components and click Install.
The RSAT tools will now begin downloading and installing on your PC. Once they are fully installed and ready to be used, they will be visible under the "Installed Features" section.