All Y1280 descend from a man who lived 5100 BC, likely a farmer living in South Asia.
“The earliest Neolithic sites in South Asia are Bhirrana in Haryana dated to 7570-6200 BC,[31] and Mehrgarh, dated to between 6500 and 5500 BC, in the Kachi plain of Baluchistan, Pakistan; the site has evidence of farming (wheat and barley) and herding (cattle, sheep and goats). “
The R2 lineage of Y1280 likely was already living in South Asia at the beginning of the bottleneck in 5400 BC because there is deep diversity in Arunchal Pradesh in its sibling Y1334 which diversified at the same time.
Their parent V3714 may also have already been living in South Asia by 6500 BC.
I chose to focus on Y1280 because there is less Middle Eastern presence in its lineages compared to these other groups. This same pattern of Neolithic migration from Iran to South Asia followed by later migrations back to the Middle East I have noticed in J-M241 lineage Z2432.
The greatest argument for a primary migration to South Asia followed by later migrations back west, besides preponderance of older diversity in South Asia, is that remote Arunchal Pradesh seems like an unlikely destination for later Arab / Iranian migrants.
The Sardinian prescence of YP5340 is an outlier after millennia of branching points in South Asia and points to a more recent migration. Unfortunately there are no age estimates from YP5340 all the way to Y1288. So the migration to Sardinia must have occurred well after the most recent common ancestor of Y1280 who lived 5100 BC, though it is unsure exactly when.
Perhaps an ultimate origin in Iran for haplogroup R2 is most likely (like the model suggests). It probably entered South Asia with the influx of Iranian Neolithic farmers, who likely also introduced haplogroup L as well. The presence of old clades of R2 and L in the Caucasus also hints that they diffused from somewhere in Iran.