The Brahmaputra river, which originates in Tibet, flows through China, India, and Bangladesh. When it enters India in Arunachal Pradesh, it is known as the Dihang River. Here's a detailed explanation:

Origin: The Brahmaputra river originates from the Angsi Glacier located on the northern side of the Himalayas in Tibet.

Flow through China: The river flows eastward through China's Tibet Autonomous Region, where it is known as the Yarlung Tsangpo. It traverses through some of the world's deepest gorges and is considered one of the most challenging rivers for rafting and kayaking.

Entry into India: The Brahmaputra enters India in Arunachal Pradesh, where it is known as the Dihang River. The river flows through the eastern Himalayas, and its course is marked by steep gorges and dense forests.

Brahmaputra Valley: The river then flows into the Brahmaputra Valley, where it is joined by several tributaries, including the Lohit, Subansiri, and Kameng rivers. The valley is known for its fertile alluvial soil and is a major agricultural region.

Assam: The Brahmaputra flows through the state of Assam, where it is a lifeline for the people. The river is used for transportation, irrigation, and fishing. The annual floods caused by the river are both a boon and a curse for the people of Assam.

Bangladesh: The river enters Bangladesh and is known as the Jamuna. It merges with the Ganges and Meghna rivers to form the world's largest delta before flowing into the Bay of Bengal.

In conclusion, the Brahmaputra river is called the Dihang when it enters India in Arunachal Pradesh. It is a significant river that flows through three countries and provides livelihood to millions of people.

It's dibang not dihang..
BTW I'm from arunachal