JioFi 3 is the successor of JioFi 2. JioFi 3 is having few superior features over JioFi 2.
01) JioFi 3 does have 2600 mAh battery, while JioFi 2 was having 2300 mAh battery.
02) JioFi 3 comes with OLED indicators, which provides you update about network coverage strength, battery backup. JioFi 2 was not having OLED indicators.
You can attach up to 31 devices with JioFi 3.
JioFi3 comes with removable 2600 mAh battery. From my personal experience I can say that you can use for almost 2 days nonstop.
You can get the best performance of JioFi3 up to 10 meters.
JioFi 3 do not have any particular data limit. It totally goes with the recharge plan you have opted for.