which data communication medium will be suitable for distance of 1500m with no line of sight in hilly region

Really nothing is. See http://www.digi.com/support/kbase/kbaseresultdetl?id=2051

to be precise , which equipment can be installed?

What I am saying is that NO product can provide you a 1.5km distance under Non LOS conditions. You will have to have RF LOS conditions in order to achieve that distance.

thanks for previous suggestion… LOS can be maintained so i bought xbee 15 mile coverage model… now the problem which antenna will be suitable for it