The indo-Greek kingdom existed around the regions of Afghanistan, Punjab and Kashmir and lasted until the start of the first century, so your challenge is for a Greek speaking culture arise this region and still lives there with about 150m+ people.
Note: When I say Greek speaking I use that in the looses sense, they don't have to speak proper Greek the language just has to be based on Greek like Italian, French and Spanish are based on Latin.
Also if a Greek speaking culture existed how would that effect European colonisation of India and its world view
Finally even though the indo-Greek kingdom had a hold in Afghanistan, have this culture be exclusively on the east side of the Hindu Kush.
Note: When I say Greek speaking I use that in the looses sense, they don't have to speak proper Greek the language just has to be based on Greek like Italian, French and Spanish are based on Latin.
Also if a Greek speaking culture existed how would that effect European colonisation of India and its world view
Finally even though the indo-Greek kingdom had a hold in Afghanistan, have this culture be exclusively on the east side of the Hindu Kush.