Step 1: Understanding the Concept:
The Brahmaputra River is a trans-boundary river that flows through Tibet, India, and Bangladesh. It is known by different names in different regions.
Step 2: Detailed Explanation:
\[\begin{array}{rl} \bullet & \text{In Tibet, where the river originates, it is called the Yarlung Tsangpo or simply Tsangpo.} \\ \bullet & \text{It enters India in Arunachal Pradesh, where it is known as the Siang or Dihang River.} \\ \bullet & \text{As it flows through Assam, it is called the Brahmaputra.} \\ \bullet & \text{After entering Bangladesh, it is known as the Jamuna River.} \\ \end{array}\]
Step 3: Final Answer:
The Brahmaputra river is known as the Tsangpo river in Tibet.