The console beta is a closed one, so prospective players must receive an invitation to participate. It will last just a handful of days, from April 23 to April 27. In that time, players have access to the full game.
Tomorrow's beta is the only one before the official console launch of Elder Scrolls Online, and all characters will be wiped before the June 9 release date. Players can still transfer PC/Mac characters to the console versions though.
Just last month Bethesda dropped the subscription model for Elder Scrolls Online. Surely it will result in more console owners giving the game a shot when it comes out in June.