Makes it clear when one produces (6,3)

'produces' is the definition.
('bring out' can be a synonym of 'produce')

'makes it clear when one' is the wordplay.
I cannot really see how this works, but
'makes' could be 'brings' (bringing is a kind of making) and 'brings' is found in the answer.
'it' could be 't' (abbreviation. e.g. in 'tis) and 't' is located in the answer.
'one' could be 'o' (I've seen this in other clues) and 'o' is present in the answer.
A single letter 'u' remains which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).

Can you help me to learn more?