Country that could provide us with sari? (6)
I believe the answer is:
russia
'country' is the definition.
(Russia is a country)
'could provide us with sari?' is the wordplay.
'could provide' indicates an anagram (the word provides the required letters).
'with' means one lot of letters go next to another.
'us' after 'sari' is 'sarius'.
'sarius' with letters rearranged gives 'RUSSIA'.
'that' acts as a link.
(Other definitions for russia that I've seen before include "East European state" , "Find US sari strangely in this country" , "Country bordering both Norway and China" , "Eurasian state" , "Sing US airs badly in the country" .)