Old man having part in conditional release (6)
I believe the answer is:
parole
'conditional release' is the definition.
(I've seen this in another clue)
'old man having part' is the wordplay.
'old man' becomes 'pa' (both can mean someone's father).
'having' says to put letters next to each other.
'part' becomes 'role' (eg a theatrical role).
'pa'+'role'='PAROLE'
'in' acts as a link.
(Other definitions for parole that I've seen before include "Promise - conditional release" , "Lop ear (anag.)" , "Release (a prisoner) on the promise of good conduct" , "Conditional release from prison" , "Release of prisoner promising good behaviour" .)