Jesus this is long.
tldr for part one is: Jio is 4G only and that means all calls are VOIP(ish), and you only have to maintain the data network. This allows them to offer much cheaper data to their subscribers, and hence a bunch of new Indians are coming online.
tldr for part two is: the parent company is a retail giant and there’s a hope that they’ll be able to leverage the network to sell physical products to the new Cyber Indians.