Cognomen Ruca (Ruka 
, Ruca 
, Rauke 
) , worldwide, is a common surname. The cognomen Ruca is characteristic of Albania, where it is quite a common surname, Latvia, where it is quite a rare surname, and Nigeria. Not in comparison with a country's population, it is the most numerous in Nigeria, India, and Indonesia. Likewise, Ruca is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Ruka | Indonesia, South Africa, Nigeria, India, Albania |
| Ruca | South Africa, Angola, Poland, United States, India |
| Rauke | Germany, China, South Africa, United States, India |
| Eruca | India, United States |