Wife and her parents pressurising for mutual divorce

Sir, i married on 9 dec 10 as per hindu law. I have 3 year old son out of said mrg. Just before one month of mrg my wife refused to Marry me and said she wanted to marry her manager. I also refused but her parents cried and begged in front of my parents. her parents brought her back to home town and she apologised me and as it was love mrg i turned emotional and married her but we got this incident written on stamp paper from her father that if anything happens in future we can not be held responsible. But after mrg small diffrences became fights on 2 or 3 ocassions. Now her parents came my home insulted my parents over a fight between me and my wife. My wife left home n her parents took her and my son with them.since 01 mar 15 she was living at her parents house and i was in delhi. I tried 3 to 4 times to sort out this issue but everytime v fought. Now they have filed a false complaint on 28 oct 15 on different grounds like dowry and all. Police counselled us 3 times and all ocassions my wife is not ready to understand and pressurising for mutual divorce. Her parents want everything fast divorce , child custody and money for his future. I dont want to loose my child i love him a lot. I can give divorce but not child. presently we came to know that my wife has took some job in ahmedabad and left my son at her parents house. Police says if you dont give divorce they will have to lodge fir and we will be troubled then. I am fed up with high interference of my in laws and foolishness of my wife. i have tried everything to convince her msg, phones meeting but she says she want freedom and want to live life as per her wishes.ahe never pucks up phone and dont ans my whts app msgs. I am in airforce please guide me what should i do? How i can take my child with me? What will happen if they lodge fir who has to prove allegations me or my wife in that case? l never asked dowry n never gave any torture to my wife. Please help.