The free weekend includes access to all maps and modes.
If you want to shoot some people this weekend but don’t want to commit a real crime, go to jail or spend money, Ubisoft is offering a great alternative to satisfy your needs. This through a free Rainbow Six Siege weekend. From March 5-8 the whole game will be completely free, including all its designs and modes. This on all platforms.
You can get the PC version for free on Steam, Epic and Uplay. The game will be available for preload starting today. As usual all the progress you will make this weekend will be saved if you decide to buy the game later.
The following video is a bit old already and not very accurate in specifics, it shows the basic idea of the game quite well.