Initially play a part in conditional release (6)
I believe the answer is:
parole
'conditional release' is the definition.
(I've seen this before)
'initially play a part' is the wordplay.
'initially' indicates taking the first letters.
'part' becomes 'role' ('role' can be a synonym of 'part'**).
The first letter of 'play' is 'p'.
'p'+'a'+'role'='PAROLE'
'in' acts as a link.
(Other definitions for parole that I've seen before include "Promise (that prisoner is released on)" , "Promise of not escaping etc" , "Provisional release (for prisoner)" , "Give Al rope when he's released early" , "Release (a prisoner) on the promise of good conduct" .)