Hi
It appears that these properties were either self acquired or absolute properties (property obtained by your grand father either through partition or otherwise).
If it is the case of self acquired or absolute properties of your grand father, then all of the 8 children (5 male and 3 female) are entitled to a share of the property.
Also that your uncle's had paid 2 your mother's sisters (1 who got married in the year 1975 and 1 who got married in the year 1985) clearly shows that either the properties were self acquired or absolute properties of your grand father in which daughter's by virtue of section 8 of hindu succession act got a share of the property.
Shri.N.T.Ramarao in 1986 gave daughter's rights in ancestral properties also (please note the word ancestral( property descending directly from father's father, father's grand father etc without any partition for more than 4 generations)) and this was implemented in states like karnataka, tamil nadu , kerala and maharashtra.
In 2005 supreme court gave daughter's rights in ancestral properties all over india (2005 ruling).
So, in your case, your grand father having died in the year 2002, his share would have to be divided equally amongst 9 members(8 children and Your grand mother).
Subsequent to the demise of your grand mother in the year 2005, her share would have to be divided equally amongst 8 members(8 children).
If any of the 8 members (5 male and 3 female) had died in the intervening period between 2002 to as of date,
then all of the children of the deceased member will get a share of the property.
So the key points in your case are whether the property is ancestral or Self acquired/absolute properties of your grand father and then applicability of section 8 of hindu succession act.
Hope this information is useful.