In general, the down payment remains in between 20-30% of the on-road price of the vehicle and ROI varies between 9.25-11.5% and it totally depends on the CIBIL/Credit score of an individual. So, we'd suggest you walk into the nearest dealership to know the final finance quotation and documentation as they will be the better person to assist you. You can click on the following link to see the details of the nearest dealership and selecting your city accordingly - Car Showrooms.
Mini Cooper 3 DOOR is priced between Rs.34.50 - 46.90 Lakh (Ex-showroom Delhi). In order to know the approx on-road price click on the [link@https://www.cardekho.com/mini-3-door/car-price-in-new-delhi.htm
As of now, there is no dealership of MINI in Patna. However, the nearest one you can get in Delhi and Chandigarh. Click on the following link to checkout the details - Dealership.
ಕೂಪರ್ ಕನ್ವರ್ಟಿಬಲ್Rs.46.50 ಲಕ್ಷ*