Looking up Air India availability was a pain until recently. Now that they have joined Star Alliance you can find available flights with Aeroplan. Air India does not charge YQ/YR (fuel surcharges) so the best programs to book with are Lufthansa Miles & More/ANA as well as Singapore Airlines Krisflyer (1:1 Membership Rewards Partner).
Availability is superb for most flights. Flying is cheap in India though – for most routes, cash is a better use than miles.