Support at Evans Head for representative (6)
I believe the answer is:
legate
'representative' is the definition.
(legate is a kind of representative)
'support at evans head' is the wordplay.
'support' becomes 'leg' (leg is a kind of support).
'head' indicates taking the first letters.
The initial letter of 'evans' is 'e'.
'leg'+'at'+'e'='LEGATE'
'for' is the link.
(Other definitions for legate that I've seen before include "Papal envoy from Galtee" , "Vatican emissary" , "Official representative" , "Late, eg. for the papal representative" , "Envoy, maybe papal" .)