Determination is evident in assistance for ballad making a comeback (9)
I believe the answer is:
diagnosis
'determination' is the definition.
(diagnosis is a kind of determination)
'is evident in assistance for ballad making a comeback' is the wordplay.
'evident in' indicates putting letters inside.
'assistance' becomes 'aid' (synonyms).
'for' is a charade indicator (letters next to each other) (I've seen this in other clues).
'ballad' becomes 'song' (I've seen this in another clue).
'making a comeback' says the letters should be written backwards.
'aid' put after 'song' is 'songaid'.
'is' placed into 'songaid' is 'sisongaid'.
'sisongaid' back-to-front is 'DIAGNOSIS'.
(Other definitions for diagnosis that I've seen before include "Identification of disease" , "Identification of an illness" , "analysis" , "Doctor's verdict" , "medical opinion" .)