The Vietnamese Wiktionary community has voted to create a rollbacker group identical to the one at the Vietnamese Wikipedia, which was created in T31717. Rollbacker privileges would be granted or revoked by any administrator. All relevant interface messages have been translated at Translatewiki.net.
Now it is done.
@Jayprakash12345 This patch was deployed because I happened to be on IRC during the SWAT window and offered to babysit the patch, otherwise it'd probably would've been skipped. As the guidelines says, whenever you schedule a patch for deployment, please be around on the #wikimedia-operations IRC channel, otherwise your patches won't get merged even if they're added to the Wikitech page. Thanks.