Yes, Jio Phone 2 is a dual sim mobile phone. You can use 4G sim card slot with the Jio sim and another slot can be used with 2G network sim card.
Yes, Jio Phone 2 does support the Punjabi language.
Yes, Jio Phone 2 does have the speed dial.
Yes, Jio Phone 2 does have the support for the Kannada language.
Jio Phone 2 does have the 4GB internal memory. Practically, it has unlimited contact book.