Nullity is an invalidation of the marriage. While divorce takes a marriage and terminates it, nullification basically erases the marriage, as if it never existed. But you can’t pick between nullity and divorce.
The Marriage Act, 1961 (give link to the law) lists the reasons for a marriage to be voided (Section 23):
(i) Bigamy: One or both partners were already married at the time or;
(ii) Prohibited: relationship :(ie brother and sister) or;
(iii) Underage: One or both partners were under age (18 at the time of the marriage) and did not receive the approvals required by law or;
(iiii) One or both parties were:
- forced into the marriage under duress or fraud or;
- mistaken regarding the identity of the person they were marrying or the nature of the ceremony or;
- mentally incapable of understanding the nature of the marriage ceremony or the effect of the ceremony.
If there is both a request for a nullity and a request for a divorce, the court will not grant the divorce unless it has first dismissed the nullity request.