Moca is rated for 300ft point to point. an HR24 canbe a genie client, but its not a server. there has to be a HR44 or HR54 in the system to run the Genie clients.

the genie has to be 300ft or less from the server as its using moca to send the stream to the client.

I would not be confident at 275ft with typical Coaxial installations. but if the wire is good grade RG6 without any barrels or splits, you should be ok.