The geographical area of Koshi Rural Municipality is 75.98 sq km. It has a population of 43626 according to census 2011. This rural municipality has eight wards. It was formed by merging four former VDCs. It is surrounded by Bhokraha gaunpalika in the east and Saptari district in the west and Baraha municipality in the north and Bihar state of India in the south. The headquarter of this municipality is situated in Laukahi.
Being in the area of Kosi Tappu Wildlife Conservation, it has tourism potential also. The major focus of the local government here is on commercial farming and much of the resources are focused on it to enhance life of people as farmer or as workers.
The Chairperson and Vice chairperson this rural municipality are Ayub Ansari and Anita Devi Yadav respectively.