Contrite, remorseful (6)
I believe the answer is:
rueful
I believe this clue is a double definition.
'contrite' is the first definition.
(I know that contrite can be written as rueful)
'remorseful' is the second definition.
(I know that remorseful can be written as rueful)
(Other definitions for rueful that I've seen before include "Filled with regret" , "Showing good-humoured regret" , "Expressing wry regret" , "'Contrite, remorseful (6)'" , "Apologetic" .)