2nd marriage wife mental illness now separated

Dear Sir,
You can file for divorce based on the ground of "mental disorder" under the Hindu Marriage Act, 1955. The law allows for divorce if the spouse has been "incurably of unsound mind, or has been suffering continuously or intermittently from mental disorder of such a kind and to such an extent that the petitioner cannot reasonably be expected to live with the respondent." The medical records and the doctor's opinion stating that her illness is "old" and makes it "unadvisable" to have a child would be crucial evidence to support your case. The fact that she has been separated and under psychiatric treatment for the past 8 months also strengthens your claim that it's not possible to live together

Dear Client,
Section 12 of the Hindu Marriage Act, 1955, deals with voidable marriages and provides a remedy for parties who are in a void or voidable marriage. A marriage will be deemed voidable if consent is obtained by force or fraud. Force can be physical force or a threat. Fraud can be committed by the nature of the ceremony, misrepresentation of age, concealment of facts, or any other circumstance of the respondent that may have affected the consent. The consent of the guardian in the marriage of the petitioner obtained by force or by fraud will also be grounds for a voidable marriage within the purview of Section 12(1)(c) of the Hindu Marriage Act, 1955. The Delhi High Court ruled in Mamta Rani v. Sudhir Sharma (2014) that the concealment of the appellant’s mental/physical condition is a ground for annulment of marriage under Section 12(1)(c) of the Hindu Marriage Act, 1955. So, you can file a petition under Section 12(1)(c) of the Hindu Marriage Act, 1955, before the Family or District Court where the couple last lived together, such as their marital home, where the marriage was solemnized, or where the wife currently resides seeking a decree annulling a void or voidable marriage. You may consider judicial separation or divorce on the grounds of mental cruelty to resolve the matter permanently. Either spouse can obtain a decree of divorce if one spouse has treated the other with cruelty. Section 13 (1) (ia) of the Hindu Marriage Act, 1955, allows either spouse to seek divorce on the grounds of cruelty. If there is no possibility and no scope of mutual consent divorce, you can file a one-sided/contested divorce petition before the Family Court/District Court praying for a decree of divorce. However, grounds for one-sided/contested divorce reflect the various challenges and complexities that may arise in the course of divorce proceedings. It is always recommended to consult an expert divorce lawyer to get the right legal advice before filing a contested divorce petition.

Dear Sir,
You may have grounds to file for an annulment of the marriage on the basis of fraud, as the concealment of a pre-existing and severe mental illness may be considered a material fact that would have prevented you from marrying her had you known. While "cheating" is a broad term, you could pursue a civil action to have the marriage declared null and void, which is a different legal path than divorce.