The name RCA refers back to the Radio Corporation Of America (RCA), a US company that existed in the 20th century.
In 1929 this company entered the music business when it acquired the Victor Talking Machine Company. The Victor Talking Machine Company had released records on the Victor label until then. With RCA Victor being the main label of the new business, RCA wasn't widely used as a label brand until the 1950s.
In 1985 the RCA label became part of RCA/Ariola International. One year later Bertelsmann (Ariola's owner) acquired 100% of RCA from General Electric and created the Bertelsmann Music Group. Since then, the RCA label has switched owners twice. First it became a label of Sony BMG Music Entertainment and nowadays it's one of Sony Music Entertainment's labels.