Fraternity - or red revolution! (5)
I believe the answer is:
order
'fraternity' is the definition.
(I've seen this before)
'or red revolution' is the wordplay.
'revolution' is a reversal indicator.
'red' reversed gives 'der'.
'or'+'der'='ORDER'
(Other definitions for order that I've seen before include "architectural style" , "Direct or requisition" , "Rank" , "Regulation" , "Command or request for goods" .)