Buying a car in Tamil Nadu without local address proof

I've been living in Auroville in a guest house for 2.5 months. I want to buy a car here (the nearest showrooms are in Cuddalore and Chennai). All my documents mention my address in Delhi. I don't have a rent agreement with the guest house, I simply pay rent at the beginning of the month. Any idea how I can do this? Would an affidavit signed by a notary saying I live in XYZ Guest House, Auroville, be enough? Or would I need to get a rent agreement? Is it possible that the dealer gets the car registered in Delhi rather than in TN?