Yes, Tecno i3 is a 4g mobile phone.
Tecno i3 Pro comes with 3050 mAh battery which is sufficient to last for the whole day.
Yes, you can use Jio sim card in Tecno i3 Pro.
Tecno i3 and Tecno i3 Pro are very different. The main differences are as below:
01) Tecno i3 has 2GB RAM while Tecno i3 Pro has 3GB RAM.
02) Tecno i3 does not have fingerprint sensor while Tecno i3 Pro has fingerprint sensor.