The Sutlej River is a tributary of the Indus River system, not the Ganga. Bhagirathi is a headstream of the Ganga, Ghaghara is a major left-bank tributary, and Damodar flows through the Ganga basin (joining via the Hooghly). The Sutlej originates in Tibet and joins the Indus in Pakistan, making it geographically part of the Indus system.