How to dispose wife petition

I have a divorce case running at chennai family court since September 2015. My marriage had taken place on 01-07-2008. Now I revealed that she got married to another person without taking divorce . The marriage registration is done on 16-03-2017 but marrage date given is 03-04-2008.They have intentionally put marrage date 4 month prior to my date of marriage so that I will regarded as second husband and she will take easy divorce. I made RTI and came to know that the only evidence she had provided before marriage register is marriage invitation card which can be furged. Can I proceed with order 7 rule 11 of CPC for disposal of petition for not disclosing another marriage or can I file bigamy 494 . Kindly guide. Can I file the same in family court and this will be original petition or suit. Regards PK