Rongmandiu is a village in Donka tehsil in district of Karbi Anglong, Assam, India. As per the data provided by Census of India in 2011, total population of Rongmandiu was 326 which includes 172 males and 154 females. Rongmandiu covers 75.81 ha area. Pincode of Rongmandiu is 782486.