Father takes part in release (6)
I believe the answer is:
parole
'release' is the definition.
(I know that parole is a type of release)
'father takes part' is the wordplay.
'father' becomes 'pa' (pa can mean dad or father).
'takes' means one lot of letters go next to another.
'part' becomes 'role' (eg a theatrical role).
'pa'+'role'='PAROLE'
'in' is the link.
(Other definitions for parole that I've seen before include "Give Al rope when he's released early" , "Conditionally release" , "Lop ear (anag.)" , "Promise of not escaping etc" , "Provisional release (for prisoner)" .)