Call on model after six (5)
I believe the answer is:
visit
'call on' is the definition.
(synonyms)
'model after six' is the wordplay.
'model' becomes 'sit' (e.g. for a painting).
'after' is a charade indicator (letters next to each other).
'six' becomes 'VI' (Roman numerals).
'sit' put after 'vi' is 'VISIT'.
(Other definitions for visit that I've seen before include "Come to see" , "Inflict" , "Drop in; frequent" , "Look up" , "Call on - stay" .)