Sarlahi, a part of Madhesh Province, is one of the seventy-seven districts of Nepal. According to new laws, a combination of more than two or f…Sarlahi, a part of Madhesh Province, is one of the seventy-seven districts of Nepal. According to new laws, a combination of more than two or four villages makes a municipality, which covers an area of 1,259 km² and had a population of 635,701 in 2001,769,729 in 2011 and 862,470 in 2021.