It's impossible for us to know for sure. but contrary to popular belief, the population of the Turks was not a few thousand people. And the migration of Turks to Anatolia did not happen all at once. This migration continued from the 8th century to the 17th century. Before the Seljuks came to Anatolia, the presence of Turks in the Byzantine army is known. At that time, there was little immigration from the Balkans and the Caucasus, the real migration started when the Seljuks entered Anatolia.

"....at the end of the thirteenth century, a group of 60,000 households was in Sürmeli-Aras, and another group of 60,000 households went to Bayburt, Erzincan and Antep it spread as far as. Before 1261, there were 200,000 tents in the Denizli region, 100,000 in the Kastamonu region, and 30,000 between Kütahya and Karahisar...."

Considering that there were 3-4 people in each tent, the population of the Turks was also high. Of course, other peoples (Not just Greeks) in Anatolia were in the majority, it is estimated at around 5 million. When the Turks entered Anatolia, some migrated, some mixed with the Turks. It's pretty complicated and detailed. If we look genetically, the Anatolian people were not Greek, but the Hellenized native Anatolian people. In DNA tests of Turks, they are modeled as native Anatolian people and medieval Oghuz Turks. The Greeks are not in this group.