File police against your father for criminal intimidation if he has threatened to kill you 

Act as mentioned herein above 

You can call the police helpline for assistance 

Is he threatening to kill you, then you can approach the nearest police station and give a complaint and seek protective.

You were advised to approach police and seek  police protection

You can approach the top police officer if you suspect your father to influence the local police station and seek help from the city's top police officer.

You can approach the local police immediately with your mother and sister and a complaint against your father

Ask your mother and sister to file police complaint against father for his threats to kill you all 

- Why you are not approaching to the police 

- You can approach the Higher police official for protection of you and family members

- If police refused then file a complaint before the magistrate in Court for getting protection and to arrest him . 

- Further, if you cannot approach the police then ask some known person to inform the police for the same 

You need to file a complaint before local police and also cc it to commissioner of police for the same

Dear client,

Sorry to hear about your situation. Report the threat and give them all the pertinent details by calling the emergency hotline (100). You might also want to let other reliable people know, such neighbors, family, or friends, who can help and support you. 

Hope this helps you.