In the country, right on river in Russia (5)
I believe the answer is:
rural
'in the country' is the definition.
(rural means in the countryside)
'right on river in russia' is the wordplay.
'right' becomes 'r' (common abbreviation).
'on' says to put letters next to each other.
'river in russia' becomes 'ural' (the Ural is a Russian river).
'r'+'ural'='RURAL'
(Other definitions for rural that I've seen before include "Bucolic; pastoral" , "Countrified" , "covering the country" , "Sort of dean" , "Countryfied" .)