Abuse of Domestic Violence Act

Recently my brother and sister-in-law had very bitter quarrel. My brother was drunk and they fought for silly reasons, then my sister-in-law start breaking house hold stuff (Washing Machine & Refrigerator). To control her (my sister-in-law), my brother slap her. She left home next day and did not return. Her mother had registered missing complain in police station. Police call my brother, beat him and ask him where is your wife. My brother didn’t know where she was. Her mother and sisters knew where she was but they didn’t inform police. After 4 days she return to her mother home. They (her family member) take her to police station and missing complain closed by police. They (police) had taken my brother signature on couple of form / paper and didn’t inform him where she was and on what paper / form they are taking his signature. After repeatedly requesting they told if you ask one more question I will beat you severely. He signed all form / paper without further question. She is now staying with my brother but want to trouble us more. My mother and father decide to stay some time with my brother. Her mother has advise her to drink (small portion) of phenyl and hospitalized, so that they can again complain and take every member of family behind bar. Their intention is not good. Don’t know what will happen and police are worst, they don’t listen. Don’t know why but they support her and her family member out of way. Don’t know why. They are rich that we know. Then can spent some money. We come to know that they have choreograph this entire drama and want to take it further. We also come to know that they have one legal adviser. Can anyone try to understand our situation and give us legal advice? Your can send your advice / suggestion @ vora231@gmail.com