What do you call a playback singer in Hindi?

In Hindi, a playback singer is called a "गायक" (Gaayak) for a male singer and "गायिका" (Gaayika) for a female singer.

You can also use the term "प्लेबैक गायक" (Playback Gaayak) or "प्लेबैक गायिका" (Playback Gaayika) for emphasis.