Reported restriction on country, one in Asia (8)
I believe the answer is:
thailand
'one in asia' is the definition.
('Thailand' is part of 'asia')
'reported restriction on country' is the wordplay.
'reported' shows a homophone (sound like).
'restriction' becomes 'tie'.
'on' is a charade indicator (letters next to each other).
'country' becomes 'land' (synonyms).
'tie' is a homophone of 'thai'.
'thai'+'land'='THAILAND'
(Other definitions for thailand that I've seen before include "Asian nation" , "Southeast Asian country" , "Phuket's location" , "Formerly Siam" , "Country in SE Asia, capital of Bangkok" .)