Five inside organising rent for wine merchant (7)
I believe the answer is:
vintner
'wine merchant' is the definition.
('vintner' can be a synonym of 'wine merchant')
'five inside organising rent' is the wordplay.
'five' becomes 'v' (roman numeral).
'inside' becomes 'in' (**).
'organising' is an anagram indicator.
'rent' with letters rearranged gives 'tner'.
'v'+'in'+'tner'='VINTNER'
'for' acts as a link.
(Other definitions for vintner that I've seen before include "Wine merchant" , "A wine-merchant" , "Wine seller" , "Wine producer" , "one in red and white?" .)