Child custody

I have a child of 10yrs 3 months age and I have been married for 12 years now. From the beginning of our married life, we (I and my wife) were having issues and whenever there is an issue she behaves very adamantly. She doesnt talk to me for months and stay from me in the same house. I took to the notice of my in-laws as well as my parents. Whenever i do this, the impact and force on me will be much more than before. For the past two years it has gone beyond my control and she started humiliating me and ill-treating me. I offered many times for a marriage counseling, but she denied. She doesnt want to listen to any one. Now she left to her parents taking my kid. Even though my kid wanted all of us to live together, she forced him and took away with her. It has been nearly two months since they are living in her parents place. I have no access to my son. She picks up my call only when she wishes to. I miss my son so much. We are not in any legal proceedings. Given this situation, how would I get access to my son. Can I get his custody? She is behaving as though she is the only parent and not letting me know on his developments.She admitted him in a school and didnt let me know. I am worried she would bring up my kid in the same style she is. He is now cut off from my side of the world. Please suggest how to proceed in this context.