Family name Ratankumar (Ratankumar 
) , globally, is a rare cognomen. The surname Ratankumar is habitual in Southern Asia, particularly India, where it is a very rare surname. More frequently, Ratankumar is the forename as well as the last name.
De, Gupta, Ghosh, Nandi, Yadav, Mandal, Maiiti, Mondal, Sarkar, Chanda, Barman, Biswas, Partra, Thalia, Agarwal, Agrawal, Pardhan, Haladar, Majumdar, Bhowmick, Pramanik, Mukherjee, Dutta, Patra, Basak, Singh, Sau, Sen, Bag, Kar, Pal, Ray, Dev, Dey, Das, Saha, Chowdhuri, Shaw, Bera, Dhar, Giri, Jana, Nath, Manna, Maiti, Majhi, Sahoo, Sheet, Basu, and Chakraborty