Sorry if this has been discussed before, but can anyone give me an overview or point me to some reading material with the latest information regarding the role R1b lineages may have played in the eastern expansions of the Indo-European people?

From what I have read and can observe it seems R1a was predominant in spreading the Indo-Iranian lineages into Central and South Asia, but were R1b lineages also involved in this process? What do we currently know regarding the Tocharians, Tarim Basin people, Yuezhi, etc. that were in contact with the Chinese and connected to the Kushan Empire? Looking at online maps of R1b it appears Turkmenistan and Sogdia in Tajikistan and surrounding areas of the Tarim Basin have some R1b but it looks pretty sparse in India. Is there currently thought or known to be any R1b lineages in India connected with the Indo-Aryans?