In 2011 due to job transfer, me and my wife were shifted to Calcutta. After couple of months, she went to her parent house in Tripura with my daughter. I hard that she is involved in an "emotional affair" with her close relative. She has changed her phone number for last 3 years. She started a job there in a private school and closed all type of communication with me. She denied my money order. I tried to contact that that school and but school authority said they has no permission to share her phone number. All posted letters back to my postal address for many times since my wife did not accept them. I tried to contact her relative via social media but he threatened me negatively. I have that chat history.
I don't know what is the legal step. It has been around 3 years. I think this relationship is dead. How can I get a divorce? Please help.