Process - Second hand bike

Hi guys Generally how should the deal be done when buying a used vehicle, as far as I have known it is Pay for the bike - Take handover of bike from seller and initiate RC transfer by signing Form 29 and Form 30 I was searching for a bike for my friend who is looking to buy a used vehicle, but this guy from OLX wanted us to pay the money and wait for RC transfer till handover of the bike. Please let me know if we're wrong about the process.