The Kosi River is a prominent tributary of the Ganges (Ganga) River.
The Ganga and Brahmaputra are the two major river systems of India.
The Ganga originates as Bhagirathi from the Gangotri glacier in Uttarakhand.
Alaknanda River originated from the Himalayan region joins Bhagirathi at Devprayag, and from this point, it is known as 'Ganga'.