Explanation

The largest river in Pakistan is the Indus River.

It is the National River of Pakistan

The Indus River starts in Tibet

It originates from the Mansarovar lake

They flow through India, Pakistan,

It finally falls into the Arabian Sea near Karachi.

They start making a delta near the city of Thatta

The old name of the Indus River was Sindhu

There 6 Barrages constructed in the Indus River

The Length of the Indus River is 3,180 km

The 2nd source of  Indus River is Gar Tsangpo

The upper Indus Plain starts from Kalabagh

The upper Indus Plain ends at Mithankot 

Additional information:

The second longest river of Pakistan is Sutlej river.