Troy was 1000 BC -- way before proto-Celtic. You could call them Indo-Europeans, but then the Greeks were also Indo-Europeans. at the time of the Illiad, northwestern Anatolia would have been partially Hittitie / Mitanni
The Ironage begins 1000 BC - 750 BC in many places. This is when the sea-going Celts came to be known in the Mediterranean. According to Galician sources the last Celtic invasion of Ireland departed from the coast of Spain circa 700 BC (some sources place this at 500 BC, and all that means is the "invasion" might well have occurred over a very long span of time.