Fix theatre company broadcast (6)
I believe the answer is:
repair
'fix' is the definition.
('repair' can be a synonym of 'fix')
'theatre company broadcast' is the wordplay.
'theatre company' becomes 'rep' (short for 'repertory theatre').
'broadcast' becomes 'air' ('air' can be a synonym of 'broadcast').
'rep'+'air'='REPAIR'
(Other definitions for repair that I've seen before include "service" , "retire" , "Go - fix" , "Patch up" , "darn?" .)