Riga is a Sub-District (Tehsil/Block/Mandal) in the Sitamarhi District of Bihar. As par Census 2011 information the sub-district code of Riga is 01070. There are about 17 sub-districts in Sitamarhi and Riga is one of them. Bairgania, Bajpatti, Bathnaha, Belsand, Bokhara, Charaut, Dumra, Majorganj, Nanpur, Parihar, Parsauni, Pupri, Runisaidpur, Sonbarsa, Suppi, Sursand etc. are other sub-districts in Sitamarhi.There are about 39 villages in Riga sub-district, which you can browse from villages list.