In India, the capacity of a person to marry is determined by personal law. There is no uniform civil code and the law relating to marriage differs from community to community. Each of these laws states that an "idiot" is incapable of marrying. However, the interpretation of "idiot" by court leaves some to marry. Yet the marriages of all persons with mentally challenged can be challenged on this ground.
Hindu law, Parsi law and the Civil law of marriage lays down that a person may get married, if however due to the unsoundness of mind he is not incapacitated from giving a valid consent to the marriage, that is, he comprehends the nature of the ceremony and the obligations and consequences of the marital relationships. Even if the person is capable of giving a valid consent he may not marry if he is suffering from mental disorder of such kind and to such an extend that he is unfit for marriage and procreation of children.
Mental disorder has been defined to include arrested or incomplete development of the mind. Such a marriage is void under the Civil and Parsi law but voidable under the Hindu Law.
If either party is an "idiot" or a lunatic at the time of marriage, Christian law does not permit the performance of marriage. The marriage if solemnized is voidable.
Muslim law permits the marriage of persons of unsound mind on the basis of their guardian's consent.
With reference to marriage between a person with mentally challenged with a non-challenged person:
Law does not consider such marriages desirable.
All personal laws do not find these marriages equally undesirable.
Void marriage - has no legal existence: thus some economic benefits such as maintenance, succession would not ensue in such marriages. After 1976, children born out of void marriages are to be conferred legitimacy.
Voidable marriage - unless the non-challenged spouse goes to the court for avoiding the marriage, it remains valid. No kind of a legal choice on capacity/ desirability of persons with MR has been made.
Procreation
Children may not be desirable in this case, as it would leave the system too overburdened with the responsibility to rear them as well.
The legal status of the children in an MR - non-MR marriage is different under different laws.
The special marriage act was amended in 1976, which confers legitimacy on children born of void marriage.
Under the Christian marriage law, children born of void marriage are still illegitimate.
Under the Hindu law the children are legitimate.
Under the Muslim law the children are legitimate as the marriage is sanctioned.
If the marriage is declared void, the children can inherit from biological parents but not from ancestors. Parents can will anything to the children.
Divorce
In case of divorce, maintenance and succession is not obtained in both void and voidable marriages i.e. null marriages. Voidable marriages remain valid until the non-MR spouse goes to the court for avoiding annulment within one year of marriage. This happens under the Hindu law.
In non-valid marriage, persons other than the two partners can move to the court to declare it void. If marriage is valid, the wife would inherit in preference to the siblings of the husband. If marriage is not valid, the brother or sister of the husband could displace the wife.
In a voidable marriage, challenge by persons other than the two parties is not permissible. In marriage between MR and Non MR the marriage is void/ voidable. Therefore the divorce issue does not arise under the SPA, CMA and Hindu Act.
Annulment/divorce between two MR adults does not exist, as the marriage has not been defined. The reason for inclusion of this law is that it gives protection for both MR and non-MR person if either party wants to get out of the arrangement.