According to Section 507 of the Indian Penal Code 1860,
Criminal intimidation by an anonymous communication — Whoever commits the offence of criminal intimidation by an anonymous communication, or having taken precaution to conceal the name or abode of the person from whom the threat comes, shall be punished with imprisonment of either description for a term which may extend to two years, in addition to the punishment provided for the offence by the last preceding section.