Rampaging on a riot in province (7)
I believe the answer is:
ontario
'province' is the definition.
(province of Canada)
'rampaging on a riot' is the wordplay.
'rampaging' is an anagram indicator (I've seen this in other clues).
'on'+'a'+'riot'='onariot'
'onariot' anagrammed gives 'ONTARIO'.
'in' acts as a link.
(Other definitions for ontario that I've seen before include "Canadian province and Great Lake" , "vast lake" , "Smallest of the Great Lakes" , "Province of SE Canada, and a Great Lake" , "one of the provinces" .)