Wife conceal First marriage

Dear Sir, I am married from last 10 years and father of two children. I recently got to know that My wife and her family has concealed her previous marriage which was registered in 2002. Also our Marriage is registered in 2009, at that time also she and her family concealed the truth. Also I got the evidance that she is not divorced legally with her first husband. I need your guidance on below points- 1) She never understands me and my family in all these 10 years.We argued frequently. I always lived in doubt that why her behaviour is like this. I am actually mentally tourtured by her.She is also a big lier, due to this I lost relations with my family friends. 2) I want the custody of my both children as I cannot take risk for them, cannot left them in criminal family. 3) I have purchased a flat and got that registered for both of us, Registery has both names, will she can still claim that. 5) My marriage is illegal can it be void easily. FIR under 420, 494, 495, 496 also registered in police station. 6) Case filed in family court, they have refused the first summon. Please guide me , I am in so much mental pressure, not able to decide what is good for my and my children life. How much average time takes in court to declare nullity if prooved.