What is the original language of Injeel?

Answer 1

The Injeel that the Qur'an refers to, a book revealed by Jesus to the people in the way the Moses revealed the Pentateuch, is an artificial creation of the Qur'an. No such book has ever been found nor has there been any attempt to write such a book. As a result, it has no original language, since it was never written.

If the question wishes to ask what the original language of the Gospels were as written by Matthew, Mark, Luke, and John about Jesus' life, those were written in Koine Greek, a form of Ancient Greek used by commoners in much of the eastern part of the Roman Empire.