Question3 why can you not install the server migration tools to the server running windows server 2008 r2 using the add roles and features wizard on your server running windows server 2012 r2?

After you've installed the Migration Tools on Windows Server 2012 R2, you can register the tools on a Windows Server 2008 migration source machine by running smigdeploy.exe from your Windows Server 2012 R2 migration destination machine, but you cannot install the tools on Windows Server 2008.

For full information about how to deploy the migration tools, including how to run smigdeploy.exe to get the tools registered on a Windows Server 2008 source machine, see Install, Use, and Remove Windows Server Migration Tools for Windows Server 2012.

add the following

answer; availability;