Wife avoiding care of child. How can i get custody?

My wife filed a divorce case and pressed charges of Adultery , desertion & non responsible husband . The case is filed at my home town away from the place we currently stay. All these charges are false and I have recordings and witness for the same. In reality she was careless and irresponsible mother. Since my son started going to school she completely stopped caring about him it was always me who use to take care. She would not care for child at all and leave him up to maids . Later she started working leaving all child care on me. This became the major issue and after several fights one day she left the house with my son and filed the divorce and prayed for child custody on the ground of adultery. I have filed the RCR and now planning to file for child custody as well. All the maids and My Driver have witnessed how she used to treat my son . Apart from them my neighbours are also willing to tell the truth. What are the way to take their statement which will be admissible in court ? Can I take them in front of a magistrate and record their statement ? I have Audio recording of her aggressive behaviour will it help in my claim of child ? is that admissible in court ? I have exchanged few emails with escorts and discussed the cost / availability etc. However I never was in face to face contact with any one . My wife might have an access to these emails , is it good enough to prove Adultery and win the child custody