It's meant to fool your senses into being fooled that you're being fooled. The Taj is having a liquid buffet. And yes, that means you can drink all you want.
Yes, that also means you'll have to pay. For Rs. 999, you get the best of international and domestic spirits every evening. The party lasts all month, and all you'll need to do is fill your wallet and grab a like-minded friend, or just about anybody like-minded, and get to Underdeck. Just don't get so sloshed that you end up asking for a room there, in the Taj.