So the surviving Mubai terrorist wants to be executed. What possible reason does he have for thinking that anyone should give him what he wants. His victims had no choice.
We'd be gullible if we hung this Mumbai terrorist. A far greater punishment would be to keep him alive. It might also be important to insist that he develop his education during the rest of his life by studying alternative world views.
He might even reach an epiphany where he recognises the appalling nature of his crime and atones for it by convincing people pursuing a similar path to give it up.
The longer he is alive the more we frustrate his original ambition. Surely this is something he must fear, and we must give him the time to reflect on that.