There is an open beta on the PS4 and Xbox One you can download right now however ends Jan 16th (tomorrow as of writing). However, has they have had beta problems they are looking to extend the beta so expect a few more days for it to be available.
"Dragon Ball FighterZ is an upcoming 2.5D fighting game developed by Arc System Works and published by Bandai Namco Entertainment, based on the Dragon Ball franchise for the PlayStation 4, Xbox One and Microsoft Windows."
It is due to launch January 26th so I think they need every day possible to sort their servers out before launch. Something that other game developers should take note and do more often.