Solution:The Ganga Basin is the largest river basin in India by catchment area, covering 26% of the nation's land area (861,404 square kilometres) and supporting approximately 43% of its population.It stretches between longitudes 73°02′ and 89°05' East and latitudes 21°06′ and 31°21′ North, spanning a total area of 1,086,000 square kilometres across India, Nepal, and Bangladesh.
Of this, around 79% is located within India. The basin encompasses 11 Indian states: Uttarakhand, Uttar Pradesh, Madhya Pradesh, Rajasthan, Haryana, Himachal Pradesh, Chhattisgarh, Jharkhand, Bihar, West Bengal and Delhi.