Group given hint about measure of intelligence (6)
I believe the answer is:
clique
'group' is the definition.
(I know that clique is a type of band)
'hint about measure of intelligence' is the wordplay.
'hint' becomes 'clue' (synonyms).
'about' means one lot of letters goes inside another.
'measure of intelligence' becomes 'IQ'.
'clue' going around 'iq' is 'CLIQUE'.
'given' acts as a link.
(Other definitions for clique that I've seen before include "'Exclusive circle of people, hostile to outsiders (6)'" , "Small exclusive groups of people." , "Faction" , "Small close-knit group" , "Coterie" .)