Emigre beaten up by the authorities (6)
I believe the answer is:
regime
'the authorities' is the definition.
('regime' can be a synonym of 'authorities')
'emigre beaten up' is the wordplay.
'beaten up' is an anagram indicator.
'emigre' with letters rearranged gives 'REGIME'.
'by' acts as a link.
(Other definitions for regime that I've seen before include "Governing authority or therapy plan" , "Government - administration" , "Routine" , "Dominion of emigre" , "Command" .)