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 | India, Nigeria, Albania, Indonesia, South Africa |
| Ruca | Angola, India, Poland, United States, South Africa |
| Rauke | India, United States, China, Germany, South Africa |
| Eruca | United States, India |