A river along with its tributaries can be called as river system. The Indus river system is one of the major river systems of the Himalayan rivers. The river originates in Tibet, near the Mansarovar Lake. The Flowing west, it enters India in the Ladakh. It forms a picturesque gorge in this part. Several tributaries, the Zaskar, the Nubra, the Shyok and the Hunza, join it in the Kashmir region. The Indus flows through Baltistan and Gilgit and emerges from the mountains at Attock. The Satluj, the Beas, the Ravi, the Chenab and the Jhelum join together to enter the Indus near Mithankot in Pakistan. Beyond this, the Indus flows southwards eventually reaching the Arabian Sea, east of Karachi. The Indus plain has a very gentle slope. With a total length of 2900 km, the Indus is one of the longest rivers of the world. A little over a third of the Indus basin is located in India Ladakh, Jammu and Kashmir, Himachal Pradesh and Punjab and the rest is in Pakistan. According to the regulations of the Indus Water Treaty (1960), India can use only 20 percent of the total water carried by the Indus river system. This water is used for irrigation in Punjab, Haryana and the southern and the western parts of Rajasthan.

Indus River Basin _{Image Courtesy: Wikipedia}

This video explains the Indus River System.

Some of the learners also asked:
What is the total length of River Indus?