Wife having extramarital affair wants to file for divorce

I found my wife's physical relations with other man prior marriage and post engagementwhile being in touch with me on phone long conversations. I spoke to her and we mutually decided to get separated. So I sent her to her parents place and now she has changed her mind. Her father started threatening my parents that they will put case against my mother for fake dowry harassment, I have the recordings of phone conversations. Also I have her confessions about the physical relationship recorded with me. We staying separate for more than a year. I don't want to spoil her name but at the same time I cannot live with her as I tried my best and I couldn't. I am staying in USA temporarily for my work and I understood that there is hold on the Islamic talaq process. Could someone please suggest me if I still can apply for Islamic talaq? Or should I follow Indian Legal process to apply for divorce. I cannot visit India for atleast 6months and I don't want to drag this any longer. Please advice.