Is that Sarcasm? Aryan Invasion Theory is a conspiracy by the British to divide and convert us. As B R Ambedkar says "That the theory of the Aryan race set up by Western writers fails to the ground at every point goes without saying….Anyone who comes to scrutinize the theory will find that it suffers from a ‘double infection.’ He could clearly see the implications of such ill-founded hypotheses which colonial Indology imposed on India and which Indian scholars went on repeating ad nauseam" Dravidam is reference to a geographical location like Anga, Vanga etc., rather than a race. And as you said, Ravana is in fact a Brahmin..
Let me tell u, Periyar and his bhakts are well versed in distorting facts. I once read in a stupid DK daily abt a Tamil verse sung by 'Appar', a saivaite saint in which he wishes to rape jain(Samana) women. Shocked by this, i referred to the original text. I found out that they changed words of the poem to make it mean that way!