If a false complaint is registered against you by your wife, you have two options – either to defend your case and wait for the judgement or to file a counter case against your wife and prove her wrong..
Collect as many pieces of evidence as possible
Record all conversations (voice, chat, email, letters, etc.) with those threatening and keep the originals in a safe place. It is advised not to produce the original evidence before anyone.
Collect evidence to prove that you have neither demanded dowry nor have taken it anytime.
Collect evidence to prove that she moved out of the bond of marriage for no valid reason.
Lodge a complaint to your nearest police station, detailing about blackmailing, her false allegations, and her unbearable behaviour. Request in your complaint that police should take necessary actions to stop her from making threats and abuses immediately, also tell the police verbally and in writing along with available evidence that you are facing blackmailing and threats and mental torture from your wife and/or her family, as the case maybe. Filing such a complaint early on can save you from a lot of trouble later on if you are the first one to file this.