Organised as prime location for carnival showman (10)
I believe the answer is:
impresario
'showman' is the definition.
(an impresario funds or organises shows)
'organised as prime location for carnival' is the wordplay.
'organised' is an anagram indicator.
'location for carnival' becomes 'Rio' (Rio de Janeiro is famous for its carnival).
'as'+'prime'='asprime'
'asprime' with letters rearranged gives 'impresa'.
'impresa'+'rio'='IMPRESARIO'
(Other definitions for impresario that I've seen before include "Showman" , "Entertainment manager" , "Producer of performing arts" , "theatre director" , "Theatrical entrepreneur" .)