Son's mother wants to file dv against daugher in law

Yes, Mr.Sanghavi. 

Your mother has exactly same legal rights as your wife.

Your mother can file DV against your wife.

She should also get free legal aid to file DV.

Read the following Mumbai court judgement dated 26-Sep-2014.

https://timesofindia.indiatimes.com/city/mumbai/Woman-too-can-take-daughter-in-law-to-court-under-Domestic-Violence-Act-HC/articleshow/43480213.cms

MUMBAI: It's not only a woman who is the wife or live-in partner of a male abuser who is entitled for relief under the Protection of Women from Domestic Violence Act. Even other women in a domestic relationship with him [abuser] in a shared household are entitled to it, the Bombay HC ruled on Thursday. 

In other words, a mother can now file a complaint against her daughter-in-law or daughter. Also, a woman can file a case against her sister-in-law and sister. 

You have not stated as to why/on what grounds your mother will file DV case on your wife.  So no Comments.