blackmailing the in-laws

Greetings,

As per your query, it is to be noted that Blackmailing is covered under Section 503 of the Indian Penal Code. According to this Section Criminal intimidation- Whoever threatens another person with any injury to his person, reputation or property, or to the person or reputation of any one in whom that person is interested, with intent to cause alarm to that person.

A person can be punished for up to three years in such cases.

It is suggested that you hire a local lawyer and send a legal notice to your son and daughter in law citing the above mentioned clause and if they fail to send a reply notice, move for legal hearings. It is advised that you retain a copy of the notice with yourself and your lawyer for future purposes.

Hope this helps.

Regards