Ubisoft and Extra Life are teaming up to create an astronomical force for good to help sick and injured kids everywhere. We’re excited to announce that starting July 1, a donation of $6 or more to Extra Life gets you Guaranteed Access to the upcoming Rainbow Six Siege Closed Beta! The Closed Beta starts on September 24th and Guaranteed Access keys will get you in on day one.
Seeing as the linked website does not say either way, I'm pretty sure that this does NOT give you a full copy of the game. As the release date of the game is the 13th October 2015, this closed beta access should be good for 3 weeks at a guess. Still a pretty good deal if you want to just try the game out, and it's going to charity. Full version of the game costs US$60.95 on steam right now.
Great idea to raise money for charity