Kalaiya is a sub-metropolitan city and serves as the headquarters of Bara District in Madhesh Province, Nepal. At the time of the 2021 Nepal ce…Kalaiya is a sub-metropolitan city and serves as the headquarters of Bara District in Madhesh Province, Nepal. At the time of the 2021 Nepal census, it had a population of 141,179 people residing in 28,645 individual households.