Group - it is composed of outlaws (7)
I believe the answer is:
bandits
'outlaws' is the definition.
(bandit is a kind of outlaw)
'group it is composed' is the wordplay.
'group' becomes 'band' (band can mean a group of people).
'it' becomes ''t' (abbreviation. e.g. in 'tis).
'composed' is an anagram indicator.
't'+'is'='tis'
'tis' anagrammed gives 'its'.
'band'+'its'='BANDITS'
'of' is the link.
(Other definitions for bandits that I've seen before include "'Brigands, outlaws (7)'" , "Violent robbers" .)