Ancestral property sold without girl child's signature

For the ancestral property, all the legal heirs have equal rights over the property.  So your grandmother did not sign, but it is elapsed 30 years.  Have you the death certificate of the parents of your grandmother and their legal heir certificate?

The issue of non-signing the sale documents by your grandmother 30 years ago is barred by limitation, no legal relief / help can be granted by courts.

Just wait for another 30 years.

Thank you Sirs, the thing is my grandmom was kept in the dark when her now deceased brother did the transaction. 

So because it's more than 30 years already, no legal relief can be sought? What's the maximum time limitation for such cases? 

Your GM ought to have filed the case within 3 years from the date of knowledge or should have sought her share in undivided property within 3 years from the date of death of the deceased parents.  There is no information on the enjoyment of the property for all 30 years and the mutation entries and some other transactions during 30 years.  Contact a local advocate on behalf of your GM and discuss with him about such possibilities.

Facts posted suggest that the property not to be ancestral, but intestate property of the parents. As such, the the property was jointly vested with the grandmother and her brother. The conveyance executed could relate only to property devolved upon, not to his sister's property. Viewed thus, the property continues to be vested with her.

As such, no limitation applies the transaction involving fraud. It could also be pleaded that the action is being instituted within the period of limitation of the transaction. The brother of the grandmother ought to be the first defendant in the matter.

The litigation is bound to be long drawn out.