Gahna Siyar is a village in Nagri tehsil in district of Dhamtari, Chhattisgarh, India. As per the data provided by Census of India in 2011, total population of Gahna Siyar was 271 which includes 129 males and 142 females. Gahna Siyar covers 508.75 ha area. Pincode of Gahna Siyar is 496220.