In the movie of 'Oblivion' Jack Harper and Victoria Olsen are clones of their former self. It isn't shown in the movie that if they can have a baby together but if we assume that there can be cloned humans, Can they reproduce or they will be sterile?
Normal clones are the same as any other biological entity, so as long as there is no genetic defect leading to sterilization, then a clone would be able to reproduce naturally.
However in the context of the movie, we don't know what kind of technology the Tet used to clone them; it can be inferred that some form of accelerated aging is used, which may damage the reproduction ability. Further, its likely that the Tet would sterilize its clones as a matter of course.
From the film Oblivion it is apparent that Jack-49 is fertile as he is the father of Julia's daughter.