Export OMF From Avid Media Composer to Reaper
Media Composer can export a sequence's audio as an OMF file for a sound editor or mixer to bring into another DAW — including, once converted, Reaper.
OMF actually originated at Avid, so it's no surprise Media Composer still supports exporting to it — it's the classic hand-off format from picture editing to audio post.
From Media Composer, use File > Export and choose OMF Interchange (or AAF, if that's what your workflow calls for — check with whoever's picking up the audio which one they need).
Reaper doesn't open an .omf file directly, so the next step is converting it into a Reaper project.
You can convert your OMF file for free here.
A 2-minute walkthrough of how to open an OMF file in Reaper, from start to finish.
Everything you need to know about OMF files and Reaper: how to open an OMF in Reaper, how OMF exports work (embedded vs. non-embedded), what they contain, what's missing, and what used to break before this converter existed.