  Scenario of a bouncing universe is one of the most active area of research to
arrive at singularity free cosmological models. Different proposals have been
suggested to avoid the so called 'big bang' singularity through the quantum
aspect of gravity which is yet to have a proper understanding. In this work, on
the contrary, we consider three different approaches, each of which goes beyond
General Relativity but remain within the domain of classical cosmological
scenario, to address this problem. The hallmark of all these approaches is that
the origin of the bouncing mechanism is somewhat natural within the geometrical
framework of the model without any need of incorporating external source by
hand. In the context of these scenarios ,we also discuss various constraints
that these viable cosmological models need to satisfy.
