Section 5 of the Hindu Marriage Act, 1955

Condition for a Hindu Marriage

A marriage may be solemnized between any two Hindus, if the following conditions are fulfilled, namely:
  1. neither party has a spouse living at the time of the marriage;
  2. at the time of the marriage, neither party,-

    1. is incapable of giving a valid consent of it in consequence of unsoundness of mind; or
    2. though capable of giving a 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; or
    3. has been subject to recurrent attacks of insanity or epilepsy;

  3. the bridegroom has completed the age of twenty one years and the bride the age of eighteen years at the time of the marriage;
  4. the parties are not within the degrees of prohibited relationship unless the custom or usage governing each of them permits of a marriage between the two;
  5. the parties are not sapindas of each other, unless the custom or usage governing each of them permits of a marriage between the two