B Class' arch rival is the BMW 2-Series Active Tourer which certainly is not offered in the country yet by BMW India. However, in India, it rivals with most of the entry level offerings from the luxury car makers.
Mercedes Benz B-class is a compact SUV, which has a ground clearance of 190mm. This much ground clearance is sufficient for even bad roads. To know more about the dimensions of the car, please visit the link below-
The ground clearance of Mercedes-Benz B Class is 538mm and it comes equipped with rear passenger VCD system. For more information on the same, kindly click on the link below: -
Mercedes are usually more comfortable and have a smoother ride. They also have more advanced technology and have many more luxury features. The Interior and exterior design of Mercedes are also mush better than the others. And even though their reliability isn't bullet proof, they're still more reliable than a BMW or an Audi.
BMW's and Audi's are usually going to offer a better driving experince. They're more performance oriented and don't normally ride as smooth. They're also not quite as comfortable when compared to a Mercedes. As far as Audi vs BMW is concerned, I say they're equal.