My sister is brain washed by unknown boy against her family .

Hello, I am akshat bhaseen, i am a law student proceeding B.A LLB HONS. ( 7 sem ) , me & my family is in great trouble , because of my adult sister who is 28 years old and is dentist . My family is finding good boy to marry her through newspaper ads, jeevan sathi app, etc . One day my sister find BBA qualify boy on jeevansathi app & she met him , she think that boy is suitable for her , but in truth when we enquire about him and his work , we find that he make false statements and false promises to my sister , he had brain washed my sister against her family by manipulating false stories , for example 1- he have big business , but in truth it is false . 2- his sister who is bigger than that boy, is getting married in Sep, but that was too false story , as they are till now finding groom for her. 3- she order my sister to give her pan number , as my sister is earning good money by working in international company . 4 - one day , when my sister is at home , that boys call her phone more than 40 times at night , but when my father come to know , he byself pick call of him at around 12.30 am or 12.45 am & talk to him , & that boy was talking in angry way . , Etc One day when my father call boy father in coerion of my sister , his father only told my father i will call back you after discussing with my son In evening , but call my father 5-6days after & told my father again i will talk to you after 12 days on 16 aug , and on 17th when his boy father call my father , my father refuse to proceed this relation of daughter to his son , as my sister told to my father if you will feel this relation fine for me than only proceed this relation otherwise leave it , so my father stop to proceed further , as he feels that his daughter will not be happy in this family as their father conservation was very horrible according to my father for my sister future . Than that boy message my sister again & start manipulating my sister , & my sister than start to fight with her family (father ,mother,sister & brother) that boy right for her etc , etc. My question is -1) i feel my sister is BRAIN WASHED (INTIMATED)(CRIMINAL OFFENCE)by that boy whom she met only 2 months before , & that boy turn my sister against her parents whom she live 28 years . My sister loves her father & mother most before 2 months , we don't know how that boy manipulated my sister. 2 ) that boy have cheated ( criminal offence ) my sister in numerous way . Like - (that boy said sister is getting married in Sep or Nov) ,that boy sister is already get roka. We found it not truth. 3) that boy is softly forcing ( criminal offence ) my sister to get married to him . In last , i have to say that my father accept my sister choice to marry him , but my sister said to father if u will agree only than i will marry her , but when my father refuses this relation is not perfect for u , than my sister again start to fight , my father even allow to marry him without our consent, but she refuse