There are no "pre-Greek" people in Greece.

If you wanna call a people pre-Greek that would be the people of Greece prior to 2200 BC.

That civization is termed "Helladic"

These people were J2 and Ev13 and would have spoken Greco-Hittite or a common IE language very similar to proto-Greek. J2 had been indigenous to Greece for 45,000 years and Ev13 for 10,000 years.

The Anatolians and "Hellads" (not to be confused with Hellenes!) split from the group about 7,000-10,000 years ago when one group Hellads(YAP linage) migrated across the Mediterranean coastline to
Cyprus and Greece and spread agriculture where they went and the other founded the Egyptian civilisation. The Egyptian civilization was J1 and E. E originated in Northern Africa, migrated to Asia and migrated back.

One tribe of the R1 linage migrated to the Balkans and after mixing with the already J2 and E there, became the proto Greeks. The Greeks of 2200 bc were already of mixed linages E, J2, R1b, and even I which was already in the Balkans.