Island nation imports south Indian snack (6)
I believe the answer is:
samosa
'indian snack' is the definition.
(type of Indian pastry)
'island nation imports south' is the wordplay.
'island nation' becomes 'samoa' (country made up of several islands).
'imports' is an insertion indicator (inserted letters are imported).
'south' becomes 's' (abbreviation).
'samoa' enclosing 's' is 'SAMOSA'.
(Other definitions for samosa that I've seen before include "Stuffed Indian pastry" , "Savoury Indian snack" , "Indian fried pastry" , "Triangular fried pastry" , "savoury pastry" .)