Yes, you can use the 4G Jio sim card in Comio C2.
Yes, you can use 2 4G sim cards in Comio C2. But at any given time only one sim card will work on 4G network.
No. Comio C2 has a dedicated MicroSD card slot. You can use 2 sim cards and 1 memory card at the same time.
Comio C2 comes with big 4000 mAh battery. It offers talk time of up to 20 hours and standby period of about 500 hours.