Outcome in Ulster uncertain (6)
I believe the answer is:
result
'outcome' is the definition.
('result' can be a synonym of 'outcome')
'ulster uncertain' is the wordplay.
'uncertain' is an anagram indicator.
'ulster' is an anagram of 'RESULT'.
'in' is the link.
(Other definitions for result that I've seen before include "Consequence or effect" , "Outcome of an undertaking" , "Rustle (anag.)" , "'Outcome, upshot (6)'" , "Effect of lustre" .)