Child maintenance for US citizen child in India

Hello, I and my husband were married 6 years . (2016 to current) He is an NRI (US). After 4.5 years of marriage we had a boy who was born in US, hence a US citizen. When my son was 8 months old , my husband threw me out of the home and I had to come back to India for my child's and my safety. He now wants a mutual divorce but doesnt want to pay child support or alimony. He and his entire family call and threaten me and my baby as well as the rest of my family. What are my rights as far as child support and alimony are concerned. I paid for the downpayment of the house in the US and have the documentation to prove it. Can he sell it without my permission? Can he take the baby to the US without my permission? What should do to make sure he continues to pay child support in India now that he is in the US? How much child support is my son eligible for? Can I file for child maintenance in California in case he doesnt pay up? I have not yet signed any documents, what should I make sure to protect my and my son's financial and physical safety? Thank you all.