Absolutely, and it should be fast. Keeping him in the prison just gives him a chance to carry out his terror network from the jail and it is a waste of the tax payer's money. In a country like India where the money could be used on welfare schemes we cannot afford to waste money and resources on a man who has no respect for other people's lives.
He should die and he should die soon, that will be the only justice to the people killed in the bomb blasts and people killed by him and his network for money.
HANG HIM TILL DEATH And do it fast. No mercy for a dreaded terrorist like Abu Salem.