Finished six deliveries (4)
I believe the answer is:
over
I believe this clue is a double definition.
'finished' is the first definition.
(over can mean finished or ended)
'six deliveries' is the second definition.
(cricket)
(Other definitions for over that I've seen before include "Work out of hours" , "Accomplished" , "Beyond; finished" , "Higher than; finished" , "completed" .)