Adopted daughter without any legal formality

I am Alka 49 yrs old and last month my father Mr. Yogender Pal Singh tried to adopt Modi ji in ref. of Mrs. Nahid Lari Khan challanged to PM to show adoption letter that he if he son of UP. In this episode one halafnama prepared and I was not included in family members , when I did oppose he clearly said that she was daughter of my late brother Surender Pal Singh who died in 1967 before she born and I just gave her my name as her father .After death of my real father Sh. Surender Pal Singh's death my mother got married with her dever Mr. Gajender Pal Singh . Now pl. give attention on the point that my grand grand father Sh. Sitaram did will in 1956 of his agricultural land to his grand sons Yogender , Surender and Gajendra . Do they ( Yogender , Gajender )have right to break the will of my father late Sh. Surender without my consent , but this happened during land chakbandi in 1968-69 and whole land was divided into two names Yogender and Gajender . I have gone through all old records and found that my grand grand father did will in favour of my father late Sh. Surender and name in all khata khatoni was till 1967 but after chakbandi in 1968-69 where has gone that name. Now I came to know that my so called father Mr. Yogender did big fraud by giving his name as my father instead late Sh. Surender and now throwing me out of his family with consent of his family members like one daughter and three son. please advice me what should I do now.