Germany would be happy to have him board a flight to Germany, where he would be arrested on arrival, the problem is that there are (now) no flights at all. India is unwilling to let a convicted criminal in the country, but he has committed no crimes on Indian soil, so they're not arresting him. In a scenario like this there's very little the German embassy can do, it's not like they have their own private jail ready.
At this point, the guy is probably best off just waiting it out in the transit area, and getting a flight out to Turkey or wherever when they resume.
At this point, the guy is probably best off just waiting it out in the transit area, and getting a flight out to Turkey or wherever when they resume.