If your parents are the victim of criminal intimidation then they alone can file the complaint against him which can result in his arrest. Your parents are also at liberty to evict him from their house by filing a suit for eviction.

1) your parents can file complaint of criminal intimidation against their son if he threatens them

2) your mother can also file application under domestic violence act and seek protection order against her son

3) in alternative. your parents can move court and obtain order directing son to vacate portion of house in his possession and injunction restraining son from disturbing their peaceful possession of the house

Yes, you may file a police complaint against him and it may be possible that police admitted him in hospital for treatment.

You cannot force them to check him into a rehab. They are the ones who have to initiate the legal process.

1) there is a senior citizen police helpline

2) you mother can call them and request them for assistance in convincing son to take medical treatment

You can apply for appointment of legal guardian by court of law if you could prove his mental illness. In the said case you can also apply for his treatment from mental health care.

you may file a complaint u/s 133 of Cr.P.C before SDM/DM regarding public nuisance but for this another person of area where he is residing should be the witness and claim nuisance created by him.

One cannot remain or live with fear due to constant threats or intimidation.

Some actions ought to be taken

Police help can be sought when he is in normal condition and tortures them but not otherwise.

Your parents should have the phone number of the mental asylum o contact them immediately in the event of things are going out of control.

Your parents have to adopt safety measures to protect themselves from the assaults and violent acts of your brother because his behavior is not continuously bad and his insane act occur occasionally, therefore there can be no permanent solution for this except to get him admitted to mental asylum whenever he becomes violent and vigorous and out of control.

1. Your brother is mentally ill and requires treatment and not any police action,

2. Consult with a psychiatrist and start his treatment as otherwise he may permanently go out of his mind,

3. His behaviour caused because of his mental illness will not attract any action by the police against him except maintaining law and order in your house and locality,

4. You shall have to fix a mental hospital who provides aides to take the patient to the hospital by applying physical force,

5. Inform the date of his shifting to the hospital to the police in advance.

1. No, you shall have to convince your parents for giving consent for the treatment of your brother,

2. You can request the councillor of your local municipal corporation and/or local police to help you by talking to your parents in this regard.