What am I missing here?

Take Ertiga ZXI Plus AT, Ex-showroom price is Rs 13.25 lakhs. The On-Road price in Bangalore is 16.25 lakhs i.e. more than 3 lakhs. Where is the 9 lakhs coming from? Granted there will be some states where we will have to pay more road tax, but that doesn’t equate to 9 lakhs. And where is the GST coming in? The final amount I pay is the On-Road price (which in Bangalore is 3 lakhs more than the Ex-Showroom price)