So why even make it a closed beta, then?
Rainbow Six: Siege is almost here, and before we get to the game proper, we will be getting the closed beta. Ubisoft has now opened up registrations for the closed beta of the game, and if you manage to register, you will be guaranteed a spot, as opposed to a random selection later- all you have to do is visit the Siege Games RTX beta code site and register for a key.
Once that happens, you just need to follow the following steps, and you should be good to go with playing the beta:
Of course, considering that a lot of people are registering for the beta at once, you may be put in a waitlist, but apart from that, this seems to be far more transparent than most other closed betas go.