The Bajaj Discover 125 is expected to offer a mileage of around 60 to 65 kmpl, as per the latest updates and user reports. In contrast, the specific mileage details for a "125 M" model are not provided in the available sources, but given that the Bajaj Discover 125 is known for its fuel efficiency, it is likely to provide better or comparable mileage to other models in its class. Therefore, based on the available data, the Bajaj Discover 125 would likely give more mileage.