For this, we would suggest you walk into the nearest service centres. You can click on the following link to see the details of the nearest service centres and selecting your city accordingly - Service centre.
Yes, Mercedes Benz G-Class is Powerful, its high ground clearance, suspenssions and different differential modes give it extreme off-roading capabilities and it is luxurious too. Do take a test drive in order to get better clarity. Check out authorised dealership details.