Nainsar is a village in Pharenda tehsil in district of Mahrajganj, Uttar Pradesh, India. As per the data provided by Census of India in 2011, total population of Nainsar was 4,402 which includes 2,290 males and 2,112 females. Nainsar covers 356.75 ha area. Pincode of Nainsar is 273157.