Communist holding chap to send back into custody (6)
I believe the answer is:
remand
'send back into custody' is the definition.
(I've seen this in another clue)
'communist holding chap' is the wordplay.
'communist' becomes 'red' (red can informally mean communist).
'holding' is an insertion indicator.
'chap' becomes 'man' (chap can mean a man).
'red' enclosing 'man' is 'REMAND'.
'to' is the link.
(Other definitions for remand that I've seen before include "Place of detention for those awaiting trial" , "Put in cooler" , "Return (often) to custody" , "Return to custody while evidence is being sought" , "Return prisoner to custody while awaiting trial" .)