Dowry demand and harrassment by in laws

My daughter got married with one with all Hindu Rituals. After six months of her marriage when I visited her, she was quite upset and depressed and after asking she told me that she had extensive argument with her husband and her in laws. Then I came back home. After 10 days my daughter called me up crying telling that her husband had beat her up and her mother in law was standing and watching. She also told me that they had demanded 5 lakhs dowry amount. Her father in law also said that we have to pay the same otherwise they will keep on torturing my daughter for lifetime. Sir I am from a small family and also spent a lot on their marriage and also have given furniture and electronics after marriage. Sir, please save my daughter.