Family name Ренч (Rentzsch 
, Ренч 
) , throughout the world, is quite a rare last name. The family name Ренч is habitual in Germany, where it is quite a rare surname, Austria, where it is a rare surname, and Ukraine, where it is a very rare surname. Not in comparison with a country's population, this name is the most popular in Germany, the United States, and Austria.