Reliance jio is fastest covering sim of india.about in 6 month many new user conects to it and reason is the very simple tht is its free call and data services.but there us also a problem that is network services are not provided to many plces like many villages and have vad network problem.but reliance jio has very good networks in town and gives 1 gb daily free 4g data after 1 data uses speed of net decreasesbut afterall that is very good to them who uses internet most.there is problem also tht it only work in 4g mobiles other phone and only works in 4g handset and uf u dont hv any 4g hadset then you cannot use it. So it is a requirement to have a 4g hadset to use a jio sim card.