Use the add-on widget 'Toggle button”. It toggles an enumeration attribute, so it is a sort of radio button. You only need to adjust the styling to show a radio button.
You can use images and display them based on a boolean with conditional visibility. Dynamic classes can also be used ofc. For Enumerations there is the toggle button that can be styled.
Nowadays there's this widget in the marketplace for native radio button: https://marketplace.mendix.com/link/component/116717
Radio buttons have been added to Native Mobile Resources (v.3.4.2)