Jio sim is free in any reliance digital store. It takes only one hour to start the Jio sim after the registration in reliance digital. To make calls, Jio is using VOLTE network, which is new in India. It actually means that call are made using data connection but still they need to work on their calling function. Jio speed for internet is quiet good but not that fast as 4G should be.but, I think it is beneficial for the poor students in India to learn something from internet on a free basis till 31st December 2016.