The division bench of Apex Court held as follows,

From Paras 26, 27 and 28

26. It is well settled that a marriage which is null and void is no marriage in the eye of law. Where the marriage is a nullity application for  maintenance is liable to be set aside on that ground alone. Under Section 5 of the Hindu Marriage Act, a marriage may validly be solemnized between any two Hindus, subject to the following conditions:-
(i) Neither party has a spouse living at the time of marriage [(Section 5(i) of the Hindu Marriage Act];
(ii) Neither party was incapable of giving valid consent of the marriage in circumstances specified in Section 5(ii) of the Hindu Marriage Act;
(iii) The parties to the marriage are of requisite age, that is, the bridegroom should have completed 21 years of age and the bride 18 years of age, at the time of marriage [Section 5(iii) of the Hindu Marriage Act];
(iv) The parties should not be within the degree of prohibited relationship unless the custom or usage governing each of them permits such marriage
[(Section 5(iv) of the Hindu Marriage Act];
(v) Parties are not sapindas of each other unless the custom or usage governing each of them permits between two. [(Section 5 (v) of the Hindu Marriage Act];
27. Section 11 of the Hindu Marriage Act provides that any marriage solemnized after the commencement of this Act shall be null and void and may on a petition presented by either party thereto, against the other party, be so declared by a decree of nullity, if it contravenes any of the conditions in Clauses (i), (iv) and (v) of the Section 5.
28. A careful reading of Sections 5, 11 and 15 makes it amply clear that while Section 5 specifies the conditions on which a marriage may be solemnized between two Hindus, only contravention of some of those conditions render a marriage void.

And from Para 38,

38. Learned counsel appearing on behalf of the Appellant has also argued that maintenance cannot be refused on the ground of nullity of marriage, until there is a declaration of nullity of marriage by a competent Court, in appropriate proceedings under Section 11 of the Hindu Marriage Act. We need not go into this question in view of our finding that a marriage contracted during the pendency of an appeal from a decree is not ab initio void, and certainly not when such an appeal is filed after expiry of the period of limitation.

Krishnaveni Rai Vs Pankaj Rai and Anr on 19 Feb 2020

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Citations : [2020 SCC ONLINE SC 225]

Other Sources :

https://indiankanoon.org/doc/81931264/

https://www.casemine.com/judgement/in/5e52c0a93321bc1e173f86fe

https://www.indianemployees.com/judgments/details/krishnaveni-rai-versus-pankaj-rai-anr