• Patta not broken and illegally sold having partition documents

hi venkatesh here
this about my grand mother property of my mother 
the property regarding to my grand mother 
1st  partition in 1976  after the death of grand father ( died at 1970)
partition in between my grand father family and my grand father brother family 
family partition over 

then my grand father family partition in 1979 in
 between of his childrens  and his wife (my grans mother)
7 male childrens and my grand ma

then Scheduled a b c d e f g h
My grand mother has  h  schedule 
in that 2 acers of land patta has in the name of my grand father brother name 
since now they did not break the patta after the partition done 
my grand father brother  selled that land 

this land are  shiridana marriage for doing to my mother  has written in h schedule 
but now my grand ma died
my grand father brother has died  he selled that land

how to acquire that land from third party....????