The Oxus civilisation is thought to have been Proto-Indo-Iranian and predominantly R1a-Z93. However R1b tribes did live in Central Asia before that, at least since Afanasievo. Nowadays R1b is more common in Turkmenistan than anywhere else in Central Asia, while R1a is higher around Kyrgyzstan. Yet the Oxus civilisation ranged from Turkmenistan to Kyrgyzstan via Tajikistan, so it's not clear if R1a tribes founded that culture in an area where R1b was already present, or if they came together. What we do know is that the Proto-Indo-Iranians continued west to Iran, Armenia and northern Mesopotamia, where they appear as the Mitanni from 1500 BCE.
It has also been suggested that the
Gutians, who lived in the Zagros around 2200 BCE and were described as fair-skinned and blond, were of Indo-European stock. Even their name reminds of that of other ancient IE people like the Goths (aka Gauts or Gut-þiuda) and the Gauls/Gaels/Celts. Since the Indo-Iranian called themselves Aryans and came to the Middle East with chariot-riders from 1500 BCE, the Gutians might have been an earlier R1b tribe that had migrated to the Zagros from Turkmenistan. If they belonged to R1b-L584, they might have been the ancestors of modern Armenians.
The Gutians eventually
conquered Sumer and ruled over Mesopotamia for a bit less than a century. They may also be responsible for the relatively high frequency of R1b in central-northern Iraq and in Kermanshah (west-central Iran), where R1b reaches 15-20% of the population, the highest in the Middle East after Armenia.