Here're the events and their timeline:
1) Married in May'10
2) Started living together in July'10 (in a separate house)
3) Wife was fine for a month or so
4) Started with lot of ego issues not doing household work, going out from 9AM to 9PM.
5) Insults my parents whenever possible. Started misbehaving.
6) Insults against my sister-in-law and brother.
7) Asked for 10L money from me for her mother. I refused. Since then her abuses increased a lot.
8) In Feb'11, she said that there are two men willing to marry her the next day (valentine's day). She took all gold and left the house.
9) Wanted to come back after 4-5 days but I refused until the matter is settled in the presence of community elders.
10) Meeting was arranged in Apr'11. She and her family abused and insulted me and my family in filthy language and accused us of all bad things. Meeting was inconclusive. She constantly threatened from then on with 498A etc. Abuses were common against our family.
11) In July'11 one of her relatives told us that her family is bad and my wife cheated me wrt her age.
12) Upon asking for her documents, she flatly refused to give. Note here that we were told she's one yr younger to us at the time of marriage and in our community (mostly backward but we're in a city) we never checked any documents prior to marriage which was the mistake we made.
13) I further investigated from IT dept and LIC and other depts and found that she's 8yrs elder to me. This was in Aug'11.
14) I again requested her to produce her education documents which were flatly refused.
15) Consulted a lawyer and he made further investigations and confirmed that she's indeed 8yrs elder according to her education documents. This was in Oct'11.
16) Filed case based in 13-1(1-a) and 12-1(C) in Oct'24.
17) Counselling happened twice once in Feb'12 and the other time in May'12. 

I have documents to prove that she fraudulently obtained documents (like Driving license and passport) post marriage to continue fooling us. We're also in possession of her documents mentioning her original DOB. She now started claiming that she already told us about her age prior to marriage. This is false since why would I marry someone 8yrs elder to me and also what was the need for her to take false passport/license?

Please guide on what to do. Can I get my marriage annulled for concealment of age? Can someone cite related judgements? She's supposed to file a counter next month. As soon as she files the counter, I am thinking of filing criminal cases against her (for cheating). She's also trying to prolong as much as possible and that's why I wanted to file criminal cases against her. What else can I do to succeed?

Thanks

Dont waste your time on a criminal cheating case. It would be very weakand and she would feel no presure. Instead she may retaliate with her own 498 IPC, domestic violence, 125 CrPC cases. Just focus on the civil divorce case becauseyou have a string case there. But your sister, mother, broter-in-law can file police complaints and follow it up with criminal cases. I am a lawyer practising in Delhi. Chances are she will settle the civil divorce case for a money amount that is reasonable. All the best to you. Good luck. (shpl@rediffmail.com)