It is a form for deciding the contracting state in which a particular income would be taxed as per the Double Taxation Avoidance treaty entered into between the countries. You can fill the said form even without having ITIN/EIN as it does not require ITIN/EIN as a compulsory thing to file.My above answer is subject to the limited information provided by you, we can give you a perfect answer only after having the complete data.For more information you can visit autusconsultants - autusconsultants