In India, Inter-religion marriages are performed under this Act:

The correct answer is Special Marriage Act.

Key Points

• The Parliament introduced the Special Marriage Act, 1954 which allows for a special form of marriage for the people of India to marry irrespective of their religion.
• Conditions for a valid marriage: Section 4
  • Neither party has a spouse living:
  • Neither party-
    • is incapable of giving a valid consent to it in consequence of unsoundness of mind.
    • though capable of giving valid consent, has been suffering from mental disorder of such a kind or to such an extent as to be unfit for marriage and the procreation of children.
    • has been subject to recurrent attacks of insanity or epilepsy.

Additional Information 

• The male has completed the age of twenty-one years and the female, the age of eighteen years.
• The parties are not within the degrees of prohibited relationship.
• A declaration in the form specified has to be signed by the applicants along with three witnesses.
• The Marriage Officer shall after being satisfied that all the conditions mentioned in Section 15 of the Act are met with, enter a certificate of the marriage in the Marriage Certificate Book in the Form specified in the Fifth Schedule and the parties to the marriage and three witnesses shall sign such certificate.