In data(you haven`t said what you`re playing to be more exact) there`s a file descr_rebel_factions. You need to add the revolt there(make sure all units you add for the revolts have slave for ownership in EDU or the game crashes with no message) and then you need to make an entry for the title of the revolt in rebel_faction_descr from data\text. Then you need to designate the revolt to the proper region in descr_regions(data\world\maps\base). In descr_regions the order is this for each entry:
Code:
; region tag
; settlement tag
; default culture tag
; rebel faction tag
; map RGB value
; comma-seperated resource list
; triumph point value
; base farm level
Then you need to remove the map.rwm again and start a new campaign for the changes to take effect. They`re probably not saved games compatible anyway so you might want to wait until you finish your ongoing campaign. And don`t forget to backup any file that you edit or delete, before editing or deleting it.