To Get 100% Custodial Rights Of Male Child

Hi, I was blessed with a male child just a week ago and I am a Muslim by Religion. But before my wife got pregnant there were some matters of cheating about details of wife ( Cannot be taken under legal course ) due to which I thought to divorce her after 7 months of marriage. But due to pregnancy I didn't divorce her. I didn't take a single penny as dowry and till date I myself spent money for every need of my wife and child. The family of mine is such, My Mother of age about 61 years without any illness and active, going around with daily chores. She only has diabetes, thats all and she says she can handle the child. And my sister lives in Saudi Arabia and my brother is unmarried and will get married within a year. My wife family is such, her mother, father with 2 daughters married including my wife and left with 4 sons. So which course I should take to get 100% custodial rights, whether personal law will be helpful or normal legal course of action will help?What are the charges that I may incur?