Besides the mortgagor, any of the following persons may redeem, or institute a suit for redemption of, the mortgaged property, namely:—
(a) any person (other than the mortgagee of the interest sought to be redeemed) who has any interest in, or charge upon, the property mortgaged or in or upon the right to redeem the same;
(b) any person who has any interest in, or charge upon, the property mortgaged or in or upon the right to redeem the same;
(c) any creditor of the mortgagor who has in a suit for the administration of his estate obtained a decree for sale of the mortgaged property.
Legal Commentary & Landmark Judgments: Section 91
Section 91 of the Transfer of Property Act, 1882 enumerates the categories of persons entitled to sue for the redemption of a mortgage, granting the right of redemption not only to the mortgagor but also to co-owners, sureties, and judgment-creditors having an interest in the property.
When representing a personal guarantor or co-mortgagor whose property is encumbered, file a suit for redemption under Section 91 upon tendering the mortgage debt; upon redemption, the plaintiff is subrogated to the mortgagee's rights under Section 92.