Netmarble announced the global version of Lineage 2: Revolution will be coming in June 2017 but didn't give an exact release date at that time. However, Netmarble might just reveal the release date at the press conference in Taiwan, as the publisher announced the game will be launched in Taiwan on June 14th. Since the Taiwanese version along with the English and Thai versions make up of the global version, it's possible that the English version will be released on the same date.
NA and EU players can pre-register the game's Android version at the official site. Some players from Southeastern Asia report that they can't pre-register, which means the game may block the IP. You can tell us your region and whether you are able to pre-register at the comment.