Ancestor property division

You have to  prove that the property is belongs to your grant father's property and you are all brothers are grand sons to him. You can challenge the form I and 14 by taking help from a local lawyer at your place.

My grandfather expired in 1967 so we dont have his death certificate.

Also we dont have birth certificates & marriage certificates of my uncle & father

What we have is

1.Death certificates of my father & Uncle

2.Birth certificates of all my brothers,Cousins & myself

3.Form 1 & 14 copies with only my uncle as occupant

4. And finally huge Hindu family including my G/father & fathers 1st cousins ,2nd cousins etc.

In above case what are minimum documents that i will have to gather in order prove my grandfathers relation with me.

i am from asansol (WB). we have lotof land property in asansol to the name of my grandfather.

after the death of my grand father the property divided into 5 part. grandmother and her 4 daughter

one of the daughter sold her 1/5th share to three other daughter but not to grandmother as proper sale deed

.now my grand mother died in 1986. now remaining 3 daughter claim 1/3rd share each in entire property.

she can do so?