Ubisoft announced that Rainbow Six Siege will have an exclusive multiplayer alpha for PC, but unfortunately only be available for the US and Europe. Possibly reaching to other countries later.

Participants may play PVP in a limited number of maps and modes. For the release date when it will be announced you have to visit Facebook or Twitter. Those wishing to register (although it does not make much sense) visit this link.

The Rainbow Six Siege alpha will be in English, featuring the space of 8GB and minimum requirements is:

OS: Windows 7 x64, Windows 8 x64, x64 Windows 8.1
CPU: Intel Core i5-2500K AMD FX-8120
Clock Speed: 3.3 GHz Clock Speed: 2.6 GHz
Cores: 4 Cores: 8
Release Date: Q4 2010 Release Date: Q4 2011
* CPU Score: 6479 * CPU Score: 6591
GPU: NVIDIA GeForce GTX 670 AMD Radeon HD 7970 / R9 280x
Release Date: Q2 2012 Release Date: Q1 2012
* GPU Score: 5380 * GPU Score: 5171