Can we communicate Xbee router to an another router?

XBee & XBee Gateway XBee Programamble (S2C & 900 HP)
,
1

Is it possible to communicate between routers in a ZigBee mesh network?

2

A standalone network of only Routers is not possible. There has to be a Coordinator in network.

So, to answer you question, yes communication between two Router is possible noting that there is a third module in network which is acting as Coordinator.