India has be entered by people of various cultures which has led to cultural diversity but considering the fact that the Seleucid empire had ies and friendship with Indian empires why aren't there that many Greeks in India?
The 'Yavanas' (Greeks) did have a strong presence in North India over 2000 years ago. They also had trading links with South India. Some mercenaries and artisans appear to have settled there.
Greek influence peaked under Demetrius I who reached as far as Magadha (modern Bihar) before being repelled by the King of Kalinga. Demetrius was married to a Mauryan princess. Indeed, the Greeks were generally of mixed origin. They maintained a separate identity till the time of Saka domination after which they were absorbed into various martial castes or became indistinguishable from the subject population. In remote mountain redoubts, some small communities claimed Greek origin. There are also various Rajput dynasties which have Greek princesses in their family tree. It is also possible that they appear in the 'Magha' (Iranian) Brahmin lineages.
Why did the Yavanas lose their separate identity? The answer ultimately comes down to the replacement of Greek by Bactrian and other 'Aryan' languages, consequent upon 'Scythian' & 'Hun' invasions, for all official and scholarly purposes. This extinguished the tradition of Greek Paideia which had attained high regard amongst local savants. Nevertheless, the legend of the technologically proficient Yavana continued to exercise a fascination for poets and writers of later, more settled, ages.