Regarding my father's land

Sir/madam, My father was expired in march 2005,and he had 1 acre of land on that time.this is his own property.till today his name has not changed in the registration.i have one brother and two sisters.i got marriage in some family disputes are running with this sisters and brother wants to register that land on their names only.they are saying that they wont give any part of land to this possible to register that land to their names without knowing me?they are saying you have no right to ask this this true??they are blackmailing me if you come for property we will file a criminal case against that,please tell me can i eligible to get that property or not and what should i do they are behaving like this??my mother is also for their side.she is also saying the same thing that she give my father's property to my brother and two sisters.but not to me..she already gave rupees 5 lakh to my brother and sisters which is my father's retirement amount.she didnt give one rupee to me.please give me solution.