regarding the property of great grand mother

dear sir/madam, I am the 5th generation heir of the ancestral property. i am a girl child and my father has no sons. Actually, this property which i'm talking has no land documents and still all the land taxes are being continued to be paid on the name of yerra venkata narsamma, my paternal grand father's maternal grand mother. when it was hiered from yerra venkat narsamma to her daughter sitarama , it was 150 acres of land. nearly 140 acres of that land sold off by my grand father and his mother . my grand father when he was on the death bed he wrote a will in the presence of the head men of the village stating that ,"after me my grand daughter susmitha(me) has all the sole rights on the property.my son(my father) has no right to sell it or enjoy any income through that .My wife(my grand mother) can use the income on it for her lively hood and can sell 1 acre if in case of any serious medical requirements." recently she also passed away and my father wanted the land documents to be made on his name ,as that land has no prior documents till date even on the name of my grand father.my father want the documents for some loan or any other sale proceedings.unfortunately , we have no good terms among us and i want that property for my further studies(presently pursuing my b.tech). I have no support of my paternal family i am just 20 years old. in this scenario ,what could be my action ? does the will written by my grand pa has any importance? can i get directly land documents made for me as i am a major? please help me and suggest me how to proceed in this issue.