Help father to get over bad habit (6)
I believe the answer is:
advice
'help' is the definition.
'father to get over bad habit' is the wordplay.
'father' becomes 'da' (I've seen this in other clues).
'to get over' says the letters should be written backwards (I've seen 'got over' mean this).
'bad habit' becomes 'vice' (I've seen this before).
'da' reversed gives 'ad'.
'ad'+'vice'='ADVICE'
(Other definitions for advice that I've seen before include "'Counsel, guidance (6)'" , "Opinion given about what to do" , "Informed counsel" , "Proposal for an appropriate course of action" , "tip" .)