Not many between three and six (4,2,4)

'three and six' is the definition.
I don't know anything about this answer so I cannot judge whether this works.

'not many' is the wordplay.
I cannot quite see how this works, but
'not' could be 'o' (I've seen this in other clues) and 'o' is present in the answer.
'many' could be 'five' (example) and 'five' is found within the answer.
The remaining letters 'furor' is a valid word which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).

'between' acts as a link.

Can you help me to learn more?