The Origins of Indo-European Languages

There is a system called Indo-Proto-European and you kind of know that there is a much commonality between for example that set of languages which come from Sanskrit and the European languages. In fact, as you pointed out even Sanskrit and even some of what we know as the Vedic culture has imprints of Harappan civilization. Let's talk about the Aryan migrations now. The only answer is either somebody else blotted in there or it went from this region to the rest of the world. Those are the only two answers.