RGM

by rgm do you mean rotating game mode? if so the one that's coming is based on the old crystal scar map where but there is a xerath that spawns in the center and shrines around the map that can be captured for points once you load into the game it will show you what is worth points and when the boss xerath dies in the center it will drop down a light that slowly falls and whoever is on it when it falls gets a buff if there are 2 people from different teams on it wont be captured until 1 gets off or dies and if multiple people from the same team are on it it will randomly select who gets the buff

well the rgm this week is Ascension and usually you can find these in the patch notes towards the end

Surrenderat20.net has a RGM lineup on the right-hand side that shows the upcoming RGM game type.