You can install OMSA on R7920. Please download OMSA 9.4.0 from below location and try. Windows 2016 is not a supported operating system on R7920 so I am not sure whether OM 9.4.0 will work on Windows 2016 [URL]  
Does anyone know if OMSA will run on a Dell Precision 7920 Rack machine running Windows Server 2016 or Windows 10? I have looked at a lot of Dell documentation but it's not really clear if it is supported or not. thx br
OMSA on Dell Precision 7920