Rangamati is a district in South-eastern Bangladesh. It is a part of the Chittagong Hill Tracts and the town of Rangamati serves as the headquarters of the district. Area-wise, Rangamati is the largest district of the country.Rangamati is a district in South-eastern Bangladesh. It is a part of the Chittagong Hill Tracts and the town of Rangamati serves as the headquarters of the district. Area-wise, Rangamati is the largest district of the country.