Yes, Tecno i3 does have the front camera flash.
Yes, you can use Jio sim card with Tecno i3 mobile phone. Tecno i3 is a true 4g mobile phone.
Tecno i3 has G-sensor, Proximity sensor and Ambient light sensor.
Tecno i3 comes with 3050 mAh non-removable battery, which can last a day's usage easily.