Also Romansh. Source: "Vornamen in der Schweiz. Prénoms en Suisse. I nomi in Svizzera. Prenoms in Svizra" (1993) published by the Association of Swiss registrars. https://rm.wikipedia.org/wiki/Rut_Plouda
In Polish, the usual form would be Ruta, but even then this name is rarely used. Rut is however the Polish name for the biblical figure, whose name in English is Ruth.
https://co.wiktionary.org/wiki/Rut
Pronunciation: /rut/