Can i (Wife) win a case "Child custody" because my son is with my husband and my child is 9 years nw

Hi, I am writing this questionnaire on my sister behalf, who has 10th fail and couldn’t complete her studies anymore. I am from Andhra Pradesh and being a victim of Dowry harassment and domestic violence (It’s genuine as I was harassed like hell by my husband and in laws). I have few questions which to be clarified thru your solutions. 1. I am Hindu. 2. I got married 10 years ago and have a baby boy who is 9 years old. Post my marriage, the life was fine for 2.5 years. After that, my husband started harassing me for extra dowry and used to beat me very often. He used to listen to his parents and use to beat me for no reason. 3. I couldn’t bear his torture, I came back to my parental home along with my child and stayed at my mom’s house for 4 years (No communication was there between me and my husband during this period). However, my husband wanted my son under his custody but he doesn’t want me. For that, he had a plan which got implemented later. After 4 years, through mediators, he told that he would not harass me and he would not repeat his torture. Since mediators have told me and my family that he won’t repeat it anymore, I had gone back to my matrimonial home trusting that he doesn’t repeat it. But later, what we realised was, he had called me back to his home only to take a custody of my son and had a plan to kick me out of his home. He again started torturing me like before. I had no other option except leaving my matrimonial home. Then I decided to go back to my parental home with my child. However, my in laws forcefully pulled my son from me and sent me alone to my home. 4. Again, it’s been 3 years, I have been staying with my parents lonely and there is no communication from my husband till now. Then I filed a case now 498A and DV & Dowry Harassment (A week back) against my husband, in laws and his sisters (Who were married). However, I do not have any proof that they have harassed me, all the wounds were cured. I had pics of those wounds in my mobile when I was at my husband’s place, he broke my mobile several times. Now I do not have even that. 5. How do I prove that I was harassed by them. But I was literally harassed by them. Is it fine if I tell orally in the court about the incidents happened between 4 walls, will I be succeed? 6. Now I wanted to claim my maintenance, and I wanted my son to be with me (Child custody), what are all the possibilities are there to win Child custody as the child is now with him for last 3 years. Please advise? 7. My husband’s grandfather’s property was distributed to my husband and his parents as well (my In laws). Am I eligible to claim even my in laws property as well (Because it is inheritance property and nothing was earned by themselves/in laws). Please advice? 8. My major concern is I want my son to be with me. He is my one and only hope, So that I can at least have my future alive. Thank you.