Hii I am using reliance jio sim and it is very good, the network coverage is very vast and internet speed is preety cool sometimes even more then 6mbps but sometimes speed is decreased because there are a lot of people using jio network .There is also an offer for 4G devices, we are getting 3 months of free internet, calls and messaging . So I suggest using jio network if u want a vast coverage and good internet speed . Thanks!