My 12 year old son went missing in Kolkata and I suspect kidnapping what should I do immediately

Kidnapping is punishable under Section 137 of the Bharatiya Nyaya Sanhita, and if the child is under 16, it is a serious offense. You should immediately file an FIR at the nearest police station in Kolkata, as there is no waiting period for registering a missing person complaint. The police must begin investigation immediately and inform the concerned CID or crime branch in West Bengal. Under West Bengal Premises Tenancy Act 1997, there may be additional provisions for child protection. You can also approach the Calcutta High Court under Article 226 for a habeas corpus petition if the police are unable to trace the child.