Of course Nero audio plug-in pack can't help with burning .rm video files to DVD.

Some CD/DVD software programs can burn .RM files to DVD Video disc. But please note that say FTDVD Author can create a DVD menu while DVD Santa can't.

You may also use video conversion software to convert video files like Real Media .RM video recordings to DVD format. But please note that most of them, like SUPER for example, can convert to DVD compliant .VOB files only so this won't be a final step in creating DVD disc. And while AVS Video Converter can convert all popular video files (including Real Media .rm files) to DVD and it can even burn your DVD disc, and the best thing is that it can create a simple DVD menu and DVD chapters!

If you need a DVD menu you may use DVD Authoring software. I haven't seen any DVD authoring software from major brands that supports .RM files directly, but some programs can open .RM files using AviSynth scripts.

AVS Video Editor+DVD authoring software can edit .RM files, can create a DVD menu and burn a Video DVD disc. IMHO it is the best way to convert .RM files to DVD. And it is free to try.
Although I suppose that AVS Video Converter's features will be enough for the majority of users.