If the name is of Germanic origin, it should be composed of the two elements "rad"(counsil) and "mari" (famous). I could find Radmer and Ratmar.
And there is the Slavonic name
Radomir, consisting of the two parts "rad" (with pleasure, happily) or else "raditi" (work, put together) and "mir" (peace).
I copied this last one from Das Große Vornamen-Lexikon (Duden), as I don't know anything about Slavonic languages.
Andy ;—)