First of all do your homework and figure out the difference between "personal law" and "criminal law"! I leave it upto you.
1)The Criminal Law should be the same for all people:-
In any country, the criminal law unlike the Personal Law cannot be different for different groups of people. It has to be same for all people of different groups and different religions e.g. In Islam if a person robs, his hands are chopped off. This punishment is not prescribed in Hinduism. If a Hindu robs a Muslim, what would be the robber’s punishment? The Muslim would want the hands of the robber to be chopped, while the Hindu Law would not agree.
2) The Muslims in India alone cannot separately follow the Islamic Criminal Law without involving the Non- Muslims :-
Even if a Muslim agrees, that as far as he commits a crime he should be given the punishment according to Islamic Criminal Law, it would not be practical. In case an allegation is made against a Muslim for robbery and if the witnesses are Non-Muslims, and if each one follows his own Criminal Law, the punishment in Islam for bearing false witness is 80 lashes, whereas in the Indian Criminal Law, a person giving false witness can easily escape. Thus, for a Non-Muslim to falsely accuse a Muslim of any crime is very easy, if both follow their own criminal law. However, if both follow the Indian Law where the punishment is lenient for false witnesses and robbers, it will encourage both the robber
to rob as well as encourage the witnesses to give false witness for their own benefit.
3) The Muslims in India would prefer the Islamic Criminal Law to be implemented on all Indians:- We Muslims would prefer that in India the Islamic Criminal Law be implemented on all the Indians, since, chopping the hands of a thief will surely reduce the rate of robbery in India. Similarly, 80 lashes for giving false testimony will prevent a person from giving false witness.
4) Islamic Criminal Law is Most Practical:- Islam besides pointing out a crime, it also gives you a solution showing how to prevent the crime e.g. chopping the hands of a robber, death penalty for the rapist. The punishment is so severe that it is a deterrent for the criminal to commit the crime. He will think a hundred times before committing a crime.
Thus if crime has to be reduced or stopped in India the best solution is to implement ‘The Common Islamic Criminal Law’.