Fine doctor for nursing hospital (6)
I believe the answer is:
righto
'fine' is the definition.
(both can mean 'yes' or 'alright')
'doctor for nursing hospital' is the wordplay.
'doctor' becomes 'rig' (I've seen this in other clues).
'for' becomes 'to' (eg both can mean 'in the opinion of').
'nursing' is an insertion indicator.
'hospital' becomes 'h'.
'rig'+'to'='rigto'
'rigto' enclosing 'h' is 'RIGHTO'.
(Other definitions for righto that I've seen before include "Correct" , "Agreed" , "Okey-dokey" , "OK" , "I agree (informal)" .)