will be able to form group together. Currently it is impossible to form questing group in Oceania realm.

http://us.battle.net/wow/en/forum/topic/20745655899

With Legion on the horizon, we wanted to let you know of an upcoming change that will open up additional grouping opportunities for players. As of the expansion pre-patch, players on North American, Latin American, and Oceanic realms will be able to group together in the open world no matter what realm their party or raid members are on. Players will also be able to see all available groups within the Group Finder, regardless of realm. This update will make it easier than ever for people to play together and group up for adventures like the new World Quests in Legion.

Additionally, reset timers for recurring in-game activities such as daily/weekly quests and raid/dungeon lockouts will be updated to a single unified lockout time of 15:00:00 UTC (8 a.m. PDT / 1 a.m. AEST) for all North American, Latin American, and Oceanic realms. This change will make it more convenient for players, as you will only need to keep track of one reset time. Weekly resets will occur on Tuesdays (early Wednesday mornings for Oceanic realms) at this time.