Six balls remaining (4)
I believe the answer is:
over
This clue is a double definition.
'six balls' is the first definition.
(I've seen this before)
'remaining' is the second definition.
(as in 'we ate them all but had one over')
(Other definitions for over that I've seen before include "Having gone < to America" , "See 19" , "Rouond of six bowls in cricket" , "completed" , "Half a dozen deliveries" .)