We consider a model of population dynamics with age dependence and spatial structure but unknown birth rate. Using the notion of Low-regret, we prove that we can bring the state of the system to desired state by acting on the system via a distributed control. Actually, we give the optimality systems that characterize the Low-regret control. Then we prove using an appropriate Hilbert space that the Low-regret control which is a family of controls tends to a control called No-regret control that we characterize.