In general, the downpayment remains in between 20-25 percent of the ex-showroom price of the car and it totally depends on the credit score. In order to calculate the approx EMI for Mercedes Benz GLA Class, you can click on the following link - click here
For this, we would suggest you walk into the nearest dealership as they will be the better people 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.