If you are purchasing a new car then you will get the BS6 version only otherwise the car will not get registered. And if you are purchasing a new car from the showroom then after your purchase you will get all the documents cleared, you get an RC smart card. On that, you can check if the car is BS6 compliant or BS4 compliant.
If you are planning to buy a new car on finance, then generally, a 20 to 25 percent down payment is required on the ex-showroom price of a car. However, exact confirmation regarding EMI, down payment, interest, loan period, and its procedure will be discussed by the bank or dealership only, as it depends upon individual eligibility. Click on the given link and select your city accordingly for the nearest authorized dealership details.
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.