Can we use a macro lens as a telephoto lens?

Neither of those lenses are macro lenses. They have a "macro" feature stamped on them as a marketing ploy. It just means that they focus a little closer than other lenses in their class. A true macro lens is defined as one where the subject and it's image on the film/sensor are the same size. To get that, you need to be within centimeters of your subject. Your lenses will not come close to that. Since it sounds like you really want a telephoto, don't be dissuaded by the lenses being labeled "macro". The 300mm end will be useful for wild life photos. However, you still might find that you must use some guile to get closer to your subjects.