Fraternity has trouble catching right gangster (11)
I believe the answer is:
brotherhood
'fraternity' is the definition.
('brotherhood' can be a synonym of 'fraternity')
'trouble catching right gangster' is the wordplay.
'trouble' becomes 'bother' ('bother' can be a synonym of 'trouble'**).
'catching' indicates putting letters inside.
'right' becomes 'r' (common abbreviation).
'gangster' becomes 'hood' (I've seen this before).
'bother' placed around 'r' is 'brother'.
'brother'+'hood'='BROTHERHOOD'
'has' acts as a link.
(Other definitions for brotherhood that I've seen before include "Community" , "Feeling of close kinship" , "union" , "Fraternity" , "association" .)