Yu yureka I have ordered through Flipkart with old configuration(July 2015). But I have received upgraded one(May 2016). In the box, they have mentioned 4G VoLTE, it supports voice calls in jio sim without Jio4Gvoice app.
Cons:
Heating Problem is there, u can buy strong case cover to avoid that:P
Battery backup is average, because of 2500mah.working good but I want to better features(4.4.4 is an old version) & no asking update