RTO always gives a receipt against payment of road tax and registration charges etc. I have a computerized RTO receipt for all charges paid against road tax, registration, MCD parking fee, HP Fee, etc for both my Fiats (2009 and 2012). In Delhi, you can check the online registration system (Transport Department, Govt of Delhi) for the exact charges. For my T-Jet in June 2012, I did the same and confronted the dealer about why he was quoting 20k in excess of the prescribed charges. He backed off immediately and corrected the same.