From eupedia.com:
W6: found in most of Europe, the Near East, the Caucasus, Iran, Pakistan (Sindhi, Pathan), Central Asia and India / found in Bronze Age Russia (Fatyanovo culture).
- W6a: found in Russia, Lithuania, Poland and Slovakia / found in Bronze Age Poland
- W6b: found in Britain, Germany, Turkey, Israel and Iran
- W6c: found in Greece, Turkey, Iran and Russia