I think, it is easy to converge the pressure inlet and outlet of boundary conditions but it's complicity depends on the surface conditions of geometry and also in the setup.

@ Amit, thanks for the update.

It should not be difficult at all. If it does not converge, maybe you should check the mesh and your settings.

Franco

Its not difficult. If u observe reverse flow errors at outlet faces don't worry it will not affect ur solution. In this case extend ur outlet upto few extent along length and the reverse flow error will disappear and solution will converge. But as Amit said, it will depend on set-up and boundary conditions which u have given.

@ Dinesh, thanks for the update.

May i know ,what u r trying to model and analyse?