As you know, RM files are those from Real Media. The main problem is that there are few programs for this type of file, apart from Real Media, to play them. So a tool like RM Audio Converter is always practical to have, as it lets you convert RM to other formats that are more popular and universal, and played in more players.
RM Audio Converter can convert RM to MP3, WAV, OGG or WMA. It also comes equipped with its own ID3 tag editor, so you can fill in the information in each of the resulting files. But it not only converts RM to those formats, but also does the reverse process.