Reliance Jio is a mukesh ambani company founded on 2007. Its a 4G sim card which is offering free calling, free sms, free unlimited 4G data till January. The offer is very good. To get the sim card we have to install jio app to a smartphone. Signal quality is very strong. Customer care support is not appropriate. Getting sim card is very hard. New problem I had seen in jio when we download any app from play-store the download bar kept running. Hotspot is also another thing that may give you moments of happiness and sadness alike. It is irregular to say the least. During the use I found that speed plummeted and rose on its own accord.