Yes, even before you book tickets to India via Germany, you should find out from your travel agent to get more information. If you have already book the tickets, you should visit the German Consulate to take the transit visa and also get more information. It would cost around $90 per person. Also it is important to have one when you for some reason get struck in Germany due to flight delays etc. It happened to me in Germany and the transit Visa helped me.
There was an airline strike going on in Germnay when we landed in Germany, So all flights got delayed by 24 hours. All others had a stay back in the airport, sleep on the floors, had trouble with the little kids etc. But for the people who had transit visas, Luftansa provided hotels inside Germany for stay. So it is good to take transit visa or avoid flying around that route.
If you flying by Cathey Pacific or Emirates you would not have to take one if I am right.
Hope this helps!