It is a voidable marriage. The ground is impotency. It cannot be equated with the relief of divorce, because, in the voidable marriage by a decree of nullity is passed, it amounts that no marriage has happened. Both the erstwhile husband and wife (more particularly wife, because the marriage became null and void due to impotencde of husband) can live happily as if no marriage were solemnized. Further, it can be filed immediately after the marriage, when wife came to know the impotence of the husband.
Divorce petition lies only after lapse of one year since the date of marriage. Hence, in this case, the mutual consent divorce decree is also not possible as it appears the one year has not passed at present.
What is the solution?
The husband will file the reply to the petition filed by the wife admitting the allegations and also seek the decree of nullity of the marriage. Then the court will record the statements of both husband and wife and declare the marriage as null and void.