Divorce matter

My son and his wife executed a Divorce Deed on Mutual consent in which his wife agreed not to take any alimony, maintenance allowance or any share in the property of the husband. She also agreed for the custody of two childrens (aged 8 years 6 months) with her husband. The said Mutual Consent Divorce deed was duly notarised before a Notary. She is running an "Institue of Culinary and Hospitality Management" having net income of app. Rs. 5-6 lacs p.a. but not filing any ITR. My son is employed by a Bank having net annual income of App. Rs. 8-9 lace. Now she refused to sign the petition to be filed before the competent court by denying all the contents of the Notarised Divorce Deed. 1.Now what course of action to be initiated by my son. 2. Whether the husband alone can file the suit for divorce on behalf of this Notarised Divorce Deed. 3. Whether the court will award any alimony or maintenance allowance or share in property (housing loan stands against these properties) and custody of children to the wife