Disregard what I said, I knew something was wrong:
2Fe is an element and therefore oxidation state is 0 3Cl2 would also have oxidation state of 0
2FeCl3. You assign Cl before Fe, so Cls get -1 giving them a total of -6 (because there are 6). The overall charge of the molecule is neutral and there are 2 Fes so the charges of 2Fe must equal -6. Therefore each Fe has an oxidation state of +3.
Fe increased in oxidation number so it was oxidised. Cl decreased in oxidation number so was reduced