Religious group caught in fix (4)
I believe the answer is:
sect
'religious group' is the definition.
(I've seen this before)
'caught in fix' is the wordplay.
'caught' becomes 'c' (cricket abbreviation).
'in' means one lot of letters goes inside another.
'fix' becomes 'set' ('set' can be a synonym of 'fix'**).
'c' inserted inside 'set' is 'SECT'.
(Other definitions for sect that I've seen before include "party" , "Group of people with unusual religious beliefs" , "School, faction" , "Subdivision of a larger religious group" , "Breakaway group" .)