There is a public and free (no ads either) Roku channel that anyone can download to access the content stored on their Xirvik seedbox. This is important - you can only watch whatever media you have own your server, there is no other content at all.
If you prefer text rather than video, or for advanced topics:
Install and use will be very familiar to Roku users. First, install the channel as any other channel: You can go to the channel repository in your Roku and type “Xirvik”, or you can follow this link on your browser and and click on “+Add channel”:
Then go to your Xirvik dashboard and go to Media → Roku. A simple dialog will appear asking you to enter an activation code.
Go to your TV, select the Roku input if you haven't done that already, and select the Xirvik channel. It will give you an activation code for you to type into the dashboard. Once you do that, your Roku and your seedbox will be connected and you will be able to stream whatever you have on your server.
Something to keep in mind is that the server will deliver the media files as they are, without any kind of on-the-fly conversion (transcoding). This ensures smooth playback (network conditions permitting - in general, if you can download your files faster than what it takes to play them you will be OK, for example if you can download a one hour video in 20 minutes then the speed is good enough) and low server load.
However, it comes with the tradeoff that some files may not play correctly if they're not encoded exactly as Roku needs them. In this case, you need to do a one time conversion of your video file to a Roku supported format/encoding. This is really easy to do. Go to your rutorrent explorer tab, select the file, right click on it, and then select the option to convert to Roku:
A dialog will ask you for the output directory. Default (same as input file) is OK, or you can have a directory for the Roku conversions, or organize things as you want. Then a progress window will appear:
After a few seconds or minutes, depending on the length of the video, you will have a Roku ready file you can stream directly.