Hiding first marriage

I am a divorcee and got remarried to a doctor in register office under special marriages act. She represented it as her first marriage. I had produced my divorce papers. After two months of marriage I heard about the history of this girl which goes as follows. 1. Had an affair during her school days 2. Went to Russia for studying MBBS, had a relationship, got conceived, discontinued studies, came back to India and terminated her pregnancy 3. While in India, developed another relationship, eloped with him to Pune, married and lived for 3 years with him, then left him and came back to Chennai 4. Went again to Russia and continued her MBBS came back to India during 2012 5. Started working in a reputed hospital (till now not registered to practice in India) 6. Married me in Jun 2015 hiding all her past stories (just informed me that she had a love failure and hence didnt marry till date) I am not sure whether she did a legal marriage or not but had lived with him for 3 years in Pune. What can I do in this case? Please advice.