Yes, Comio S1 does have support for Jio VoLTE also. You will be able to use Airtel VoLTE as well.
Comio S1 has got 1.3 GHz MediaTek MT6737 chipset.
Comio S1 dimensions are 149.2 x 72.6 x 7.9 mm.
Yes, Comio S1 does have a hybrid sim slot. You can either use 2 sim cards or 1 sim card & 1 MicroSD card.