Riot developed, contained by man in region (9)
I believe the answer is:
territory
'region' is the definition.
(I know that region can be written as territory)
'riot developed contained by man' is the wordplay.
'developed' indicates an anagram.
'contained by' is an insertion indicator.
'man' becomes 'terry' (I have seen 'A man' mean 'terry' so perhaps 'man' could also mean 'terry').
'riot' is an anagram of 'itor'.
'itor' going inside 'terry' is 'TERRITORY'.
'in' is the link.
(Other definitions for territory that I've seen before include "Area under the jurisdiction of a sovereign state" , "ground" , "Political land mass" , "District, colony" , "Region marked off for some purpose" .)