Marriage is a matter of personal liberty and bringing a law to curb it is completely unconstitutional. Making laws to regulate the marital relationships between two consenting adults is against constitution, will offend notion of basic freedom.
The right to marry a person of her/his choice is a fundamental right encompassed under Article 21 of the Constitution of India. Such law is nothing but criminalizing interfaith marriage for the purpose of political gains.
Laws should be framed to help people, but not to create problems for the people. Freedom of conscience and the right to practice and propagate a religion (including following any religion or not following any religion) are conferred under Article 25 of the Indian Constitution.
Moreover the law only covers cases where a Muslim man marries a Hindu woman, but not vice versa. That in itself is a violation of Article 15 of the Constitution which prohibits the state from discriminating on the basis of religion.
