at the mouth
^^^Incorrect ! A river starts at its source - usually at a high place, such as a hill or mountain. It ends at the river mouth - which is where it meets the sea.
The Mississpi River starts in Mississippi.
No river in India starts with the letter U.
No river in India starts with the letter X.
The Nile River Starts at Lake Victoria.
No river in Australia starts with the letter X.
At the souce of the river
No river in Hungary starts with the letter E.
No river in the United States starts with the letter X.
No river in Britain starts with X. If you need a river starting with X, the Xingu River is a major river in Brazil and the Xi River is in China.
it starts from melting of glacier
The source of a river is where the river starts.
It is the point where the river starts.