Cognomen Rtan (Rtan 
, رتان 
) , in the world, is a very rare family name. The cognomen Rtan is characteristic of New Zealand, where it is a very rare surname, Malaysia, and Vietnam, where it is an extremely rare surname. Measured by absolute frequency, it most frequently occurs in India, Malaysia, and Vietnam. More prevalently, Rtan is the forename as well as the last name.