adoption case

Hello, I live in Dehradun, Uttrakhand . My sister and I were born out of the wedlock. She is 1 year younger than me. Since my father is suffering with schizophrenia, he sent my sister in an adoption center in Bangalore, Karnataka. I turned 18 this year and I am living with my grand parents and none of my parents. I know only the name of the centre where she was sent but not who has her legal custody now.Every one is telling me that they will never share the details of her. Is there any way I can get the details of her adoptive parents so that I can see her from the adoption centre.