Quietly, he occupies modern male relative (6)
I believe the answer is:
nephew
'male relative' is the definition.
(I've seen this before)
'quietly he occupies modern' is the wordplay.
'quietly' becomes 'p' (p for piano and quiet).
'occupies' indicates putting letters inside.
'modern' becomes 'new' ('new' is associated in meaning with 'modern').
'p'+'he'='phe'
'phe' inserted within 'new' is 'NEPHEW'.
(Other definitions for nephew that I've seen before include "Brother's/sister's son" , "A young male relation" , "Kinsman" , "Family relative" , "Male relative" .)