Child custody

I am father of a 10 year old son. My wife left me along with my son 3 years ago on a pretext that she wants to work in delhi and started stating with her parents. In our wedlock there has been no physical abuse ever. However over trivial domestic fights she alleged that I give her emotional and mental stress. I have financially supported my wife and kid completely, infection she operated my account till now. She is working in corporate wef 2023 at a reputed position and firm probably earning more or equal. Ever since she left, she alienated me with our son. Last year onwards she completely cut me off. She wanted a desperate divorce and kept asking for the same wef 2022. But I couldn't come to terms with that. Now she has filed for child petition with 100% custody alleging that I am dangerous to my only child and have been abusive husband. Please suggest me course of action to protect my fundamental rights as a father. As I haven't been given any access to meet my son and my son and I share a very strong bond