I was in Chennai last January for business and will be there again in February. We started in northern India and just got a domestic Jet Airways flight to MAA.

On the way home, I Kingfisher MAA-BLR, then caught Air France BLR-CDG-MSP-MSN. It worked out really well.

Just make sure you are not on the last MAA-BLR flight of the evening, so if a flight gets cancelled, you don't have a disaster (esp with Kingfisher, though we used them several times to get around southern India on the ATR72s, and they were reliable for us).

Since we had 7 hours to pass, we went to the Royal Orchid Resort and Convention Centre, maybe 15min taxi ride from the airport, and caught a nap, a shower, and a nice dinner, before heading back to BLR for our flight home.