First of all go to:
Here[www.radgametools.com]
It will automatically download the tool needed to convert videos into .bik files.

Now, download your video via:
ClipConverter[www.clipconverter.cc]
or your choice of download. (I use clip converter because you can specify what times).

Now, once you open it, navigate to the file and click Bink!
then click Bink! again (Or it will say save/process or something similar).
After, drag in into your startup folder in steamapps (Tom Clancy's Rainbow Six Siege/videos/Startup)
and rename it to one of the files in there
They play in this order:
(Ubisoft first, Nvidia second)


You can get my prepacked .rar Here[mega.nz] (28 MBs)


Have fun!
Credits:
Figuring this out - Me
All other copyrighted or otherwised used go to their respective owners.