Getting round the last bit, go in (6)
I believe the answer is:
trendy
'in' is the definition.
('in' can mean trendy or fashionable)
'getting round the last bit go' is the wordplay.
'getting round' indicates putting letters inside.
'the last bit' becomes 'end' (I've seen this in another clue).
'go' becomes 'try' (both can mean an attempt).
'end' inserted into 'try' is 'TRENDY'.
(Other definitions for trendy that I've seen before include "Smart" , "With-it" , "Less sensible; a dye plant" , "Stylish" , "'Hip, fashionable (6)'" .)