I know enough about business my dear sir. There is a difference between a petro refinery and a DTH offering. Also, I do happen to know how the Ambani's got into telecom. They had a hell of a time in the beginning, but what they had going for them was initially they didn't have to pay any license fees. That allowed them to establish themselves, once that happened, the subsequent fines hardly mattered.
The Ambani's have often made their profit by stretching rules... problem is, here there are no rules for them to stretch.
Anyway, it is quite simple - they'll need to recover the cost of each LCD from each customer. It is that simple really. What could be possible is they are simply seeking to put cable operators out of business. They do have the cash reserves to do that. In that case, they can then make their money after having established a monopoly. But I doubt it will be that easy.
Moreover, the issue they'll face is the lack of premium channels. Around the world, that is how cable operators make their money (you should see the charges for HBO!). The only premium channels in India are the 50 million sports channels, and ADAG won't see any money from that (unless they manage to do what many others haven't and get a revenue-sharing deal).