Where non NI reaktor blocks are installed?
Are you referring to third party Blocks like from Toybox or Blocks from the Reaktor User Library?
If third party these come with instructions on how to install
If from the User Library you can actually put them anywhere - I just make a sub folder for them in my Reaktor User Library folder (which you can set the location of in Reaktor settings)
In whatever folder you declared at Reaktor Preferences —> Directories as "User Blocks" directory.