R1b is in Europe since the Late Paleolithic, but the R1b found in 99% of the European males who carry R1b today - subclades of R1b-M269 - certainly came from easternmost Europe after the Early Copper Age.
Now, for the umpteenth time: haplogroups are haplogroups, they are not people, and their transmission from one generation to the next generation works in a fundamentally different way from what happens to people's genome when their parents breed to make them. Read this if you want to understand what I mean:
https://qr.ae/pNoQAE
Basques e.g. have >85% R1b-L23, but the people who first had it and brought it to the western parts of Europe account for no more than ~25% of their overall ancestry. And that's talking about
genetic roots of people, not
linguistic ancestry. If Y-DNA and genomic ancestry are often very disconnected from each other, let alone linguistic identity: one language can be replaced by other even without any major genetic replacement (e.g. notice how many Irish people shifted from Celtic Irish to Germanic English in the last ~150 years alone, or how many Basque speakers shifted to French in Southwestern France in the last ~200 years).
You can't always assume that the language spoken by a people is a descendant of the original language spoken many thousands of years ago by the first males who bore the haplogroup that is NOW (but no one can guarantee it was always) the most prevalent in that population. There is no necessary causal correlation between one thing and the other. Actually, that's very often not true for many reasons: elite dominance, genetic drift, random genetic bottlenecks and founder effects, cultural shift under foreign influence, etc. I have said that multiple times in the threads created by kmak, but it seems he/she never reflects about it and never learns.
Besides, Proto-Basque was technically spoken only 2000-2500 years ago. It's impossible that the first men carrying R1b before 20,000 years ago spoke Proto-Basque, it couldn't even be a language similar to Proto-Basque even if it were really ancestral to Proto-Basque. In 20,000 years a language changes and diverges into increasingly distinct languages so much that it'd be impossible to even recognize the linguistic connection between the earliest and the latest languages easily.