Asmaka, one of the Mahajanapadas, was located on the banks of the Godavari river. Kamboja was situated in the Gandhara region, and the river Vipas (Beas) flowed through a neighboring area, but not directly through Kamboja itself. Avanti was associated with the Narmada and Sipra rivers, not the Mahanadi. Kosala was located on the Sarayu river. Therefore, two pairs (Asmaka-Godavari and Kosala-Sarayu) are correctly matched.