Fashionable team doing time (6)
I believe the answer is:
inside
'doing time' is the definition.
(I've seen this in another clue)
'fashionable team' is the wordplay.
'fashionable' becomes 'in' (in can mean fashionable or trendy).
'team' becomes 'side' (both can mean a sports team).
'in'+'side'='INSIDE'
(Other definitions for inside that I've seen before include "Inner surface" , "being held" , "Privileged" , "Behind bars (sl.)" , "Internal" .)