I just read the news a while back, where Air India was stated to have made a profit after a long time. And then, they declared a sale to celebrate the event it seems!
You are going to be able to book tickets all the way till 18 January 2015, and valid for travel from 16 January 2015 to April 30 2015. The tickets are valid for fare class E, so do look out for the E fare class on the flights.
Some of the deals are pretty sweet, like a Mumbai Delhi roundtrip flight at INR 6000. That is just wow!