Rogue artist reaching Southern California (6)
I believe the answer is:
rascal
'rogue' is the definition.
('rascal' can be a synonym of 'rogue')
'artist reaching southern california' is the wordplay.
'artist' becomes 'ra' (Royal Academician, member of Royal Academy of Arts).
'reaching' is a charade indicator (letters next to each other).
'southern' becomes 's' (abbreviation).
'california' becomes 'cal'.
'ra'+'s'+'cal'='RASCAL'
(Other definitions for rascal that I've seen before include "Villain" , "Impudent child" , "Mischievous person or confused lascar" , "Scallywag" , "Impudent person" .)