Frima Studios is currently working on the PS Vita port of Resident Evil Revelations 2, whose episodes released on PS3 and PS4 already. An update was posted on the PS Blog about the Vita version, with the announcement being made that multiplayer will not be available at release. Instead this will be added after the game’s digital release in the summer via a patch. There is no confirmed release date yet.
As for Raid Mode, single-player will also be included at launch, but online co-op Raid Mode and the ad-hoc modes will most likely come post-launch via an update. This is so we can get the full game into your hands that much sooner.
The Vita version will have all four episodes included plus DLC, except for any that is deemed to be a consumable. One of the Vita additions includes gyroscopic targetting, while other additions will be announced closer to the time of release.
Source: PS Blog