Grounds for Divorce under Special Marriage Act are as follows:

(1)Subject to the provisions of this Act and to the rules made thereunder, a petition for divorce may be presented to the district court either by the husband or the wife on the ground that the respondent”
(a) has since the solemnization of the marriage committed adultery; or
(b) has deserted the petitioner without cause for a period of at least three years immediately preceding the presentation of the petition; or
(c) is undergoing a sentence of imprisonment for seven years or more for an offence as defined in the Indian Penal Code (Act XLV of 1860): or
(d) has since the solemnization of the marriage treated the petitioner with cruelty; or
(e) has been incurably of unsound mind for a continuous period of not less than three years immediately proceeding the presentation of the petition; or
(f) has for a period of not less than three years immediately preceding the presentation of the petition been suffering from venereal disease in a communicable form, the disease not having been contracted from the petitioner; or
(g) has been suffering from leprosy, the disease not having been contracted from the petitioner; or
(h) has not been heard of as being alive for a period of seven years or more by those persons who would naturally have heard of the respondent if the respondent had been alive; or
By the wife on the ground that her husband has, since the solemnization of the marriage, been guilty of rape, sodomy or bestiality.

According to Section 13 of Hindu Marriage Act, 1955 lays down as under:
Section 13. Divorce – (1) Any marriage solemnized, whether before or after the commencement of this Act, may, on a petition presented by either the husband or the wife, be dissolved by a decree of divorce on the ground that the other party:-
i) is living in adultery; or
ii) has ceased to be a Hindu by conversion to another religion; or
iii) has been incurably of unsound mind for a continuous period of not less than three years immediately preceding the presentation of the petition; or
iv) has, for a period of not less than three years immediately preceding the presentation of the petition, been suffering from a virulent and incurable form of leprosy; or
v) had, for a period of not less than three years immediately preceding the presentation of the petition, been suffering from venereal disease in a communicable form; or
vi) has renounced the world by entering any religious order; or
vii) has not been heard of as being alive for a period of seven years or more by those persons who would naturally have heard of it, had that party been alive; or
viii) has not resumed cohabitation for a space of two years or upwards after the passing of a decree for judicial separation against that party; or
ix) has failed to comply with a decree for restitution of conjugal rights for a period of two years or upwards after the passing of the decree.
(2) A wife may also present a petition for the dissolution of her marriage by a decree of divorce on the ground:-
i) in the case of any marriage solemnized before the commencement of this Act, that the husband had married again before such commencement or that any other wife of the husband married before such commencement was alive at the time of the solemnization of the marriage of the petitioner:
Provided that in either case the other wife is alive at the time of the presentation of the petition; or
ii) that the husband has, since the solemnization of the marriage, been guilty of rape, sodomy or bestiality.