Yes, you can use Jio sim card with Tecno i3 mobile phone. Tecno i3 is a true 4g mobile phone.
Yes, Tecno i3 comes with hybrid sim slot.
No. You can use only one 4g sim card in this phone.
Tecno i3 comes with the latest Android 7.0 Nougat OS. In future, you can update phone OS if the new update gets released from the company.