Music copyright is way outside the control of Reallusion, or any of the other participating companies for that matter. As soon as you upload a video containing copyrighted content on YouTube it will get flagged by them, and that's when your problems could start to get very complicated.
Using copyrighted content in a video for your own enjoyment is one thing that you may be able to get away with, using it without permission with the goal of making money with - in this case winning a few thousand dollars in a competition - it is something else altogether.
:w00t:
Gerry
System: Win 10 Pro (21H2), Asus X99-E WS, CPU i7-5930K -3,5 GHz, 32 GB DDR4 2666-16 RAM, NVidia GTX 1080 Ti GPU - 11 GB VRAM(Driver Studio-536.99), Samsung 850 Pro 512 GB SSD, 6 TB HD storage.