How to reduce maintenance amount

I was married to my wife on 29/01/2015 under Hindu marriage Act. But soon after marriage she demanded to reside separately from my parents. My parents are old and ill and dependant on me. I tried to convince her that it is not possible for me to desert my parents and one unmarried sister. She used to visit her paternal home frequently like every week or 10 days and I had to accompany her. If I don't allow her for one week she use to quarrel with me. So I don't have any other option but to accompany her to her paternal home every week for the sake of saving the marriage. I am a government servant and she is a housewife with graduate honours qualification. She didn't even do her household duty. Even her clothes are washed by my mother. She always demanded certain amount of rupees despite the fact that I used to give her monthly payment. Then on October 2015 she left her matrimonial home with a false statement that her father was ill. Then her parents used to call me and threatened me for some unknown reason. We have tried to call her back but she refused to come back. Then finally on 9th February she filed false 498a against me and my parents. Some how we all got the bail before arrest. Soon after that she filed crpc 125 against me, for which I am preparing written objection. My gross salary is 57000. My IT deduction is Rs, 3000, PF 10000, have 2 loan EMI of 12000.So after all deduction I am getting monthly take home salary of Rs. 31000. Now my question is what prabable amount court can order for monthly maintenance to her and how should I fight the case to reduce or dismiss the petition.