Conclude with rebuke having finished (4,2)
I believe the answer is:
wrap up
'conclude' is the definition.
(to wrap something up is to bring it to an end)
'with rebuke having finished' is the wordplay.
'with' becomes 'w' (abbreviation).
'rebuke' becomes 'rap' (both can mean to criticise or reprimand).
'having' is a charade indicator (letters next to each other).
'finished' becomes 'up' (eg 'time's up' means the time is finished).
'w'+'rap'+'up'='WRAP UP'
(Other definitions for wrap up that I've seen before include "Put on winter coat, perhaps" , "Settle completely" , "Keep warm" , "Be quiet - fold paper round - finish" , "Finish off - be quiet - put on warm clothes" .)