Make good agent around company before start of upheaval (6)
I believe the answer is:
recoup
'make good' is the definition.
('recoup' can be a synonym of 'make good')
'agent around company before start of upheaval' is the wordplay.
'agent' becomes 'rep' (short for representative).
'around' is an insertion indicator.
'company' becomes 'co' (abbreviation).
'before' means one lot of letters go next to another.
'start of' suggests taking the first letters.
The first letter of 'upheaval' is 'u'.
'co'+'u'='cou'
'rep' placed around 'cou' is 'RECOUP'.
(Other definitions for recoup that I've seen before include "Make good a loss" , "Get back again, say losses (6)" , "Get back (outlay)" , "Get back, say expenses" , "make good one's losses" .)