Religious group — or part (6)
I believe the answer is:
sector
'part' is the definition.
(I have seen 'Distinctive part ' mean 'sector' so perhaps 'part' could also mean 'sector')
'religious group or' is the wordplay.
'religious group' becomes 'sect' (eg a religious sect).
'sect'+'or'='SECTOR'
(Other definitions for sector that I've seen before include ""Slice" cut from centre of circle" , "Area, division" , "Area of circle between two radii" , "region" , "A body of people who form part of society or economy" .)