Answer: Barak River
Notes: The Barak River flows mainly in southern Assam through districts like Cachar and Karimganj. It forms the southern riverine belt and is distinct from the Brahmaputra in northern Assam. The Barak basin is known for its low-lying floodplains supporting agriculture. The Brahmaputra flows through central and northern Assam, while Subansiri and Dhansiri are tributaries primarily in northern Assam.
