barak river is tributary of which river：Surma

A map showing major rivers in Bangladesh including Meghna

The Surma-Meghna River System is a river complex in the Indian Subcontinent, one of the three that form the Ganges Delta, the largest on earth.[citation needed] It rises in the Manipur Hills of northeast India as the Barak River and flows west becoming the Surma River and then flows south as the Meghna River, a total of 946 kilometres (588 mi) of which 669 kilometres (416 mi) are within Bangladesh, to the Bay of Bengal.

Meghna River Basin

From its source in the Manipur Hills of India, Liyai Village of Poumai tribe, the river is known as the Barak River (locally known as Avoure). Near its source, the river receives a number of tributaries, including the Irang, Makru, Tuivai, Jiri, Gumti, Howrah, Kagni, Senai Buri, Hari Mangal, Kakrai, Kurulia, Balujhuri, Shonaichhari and Durduria. It flows south through Manipur State, then southwest leaving Manipur and entering Assam State at Tipaimukh or Ruonglevaisuo after abruptly...