Aim to secure right artist for commission (6)
I believe the answer is:
errand
'for commission' is the definition.
(I've seen this before)
'aim to secure right artist' is the wordplay.
'aim' becomes 'end' (both can mean a goal or purpose).
'to secure' means one lot of letters goes inside another (inserted letters are secured inside).
'right' becomes 'r' (abbreviation).
'artist' becomes 'RA' (Royal Academician, member of Royal Academy of Arts).
'r'+'ra'='rra'
'end' placed around 'rra' is 'ERRAND'.
(Other definitions for errand that I've seen before include "Short assignment" , "Short journey to get or bring" , "Short journey to carry message for Renard" , "run one" , "Message run" .)