Yes, Comio S1 does have support for Jio VoLTE also. You will be able to use Airtel VoLTE as well.
Comio S1 is equipped with latest Android 7.0 Nougat.
Yes, Comio S1 does have a hybrid sim slot. You can either use 2 sim cards or 1 sim card & 1 MicroSD card.
Yes, Comio S1 does have the front camera LED flash.