Basically and legally these properties what you have mentioned are not appearing to be ancestral properties.
In fact since it is your maternal side, ther is no question of properties to be ancestral in nature as far as you and your siblings are concerned.
If your mother is alive then it is she who has to fight for an equal share in the properties that is being returned by government to the legal heirs of your grandfather, as a right.
The relinquishment deed signed by her may not be to the properties that are being acquired by your maternal uncle now on behalf of his deceased father.
Hence your mother's rightful share in the said properties can be claimed by her and in her absence, her own legal heirs can file a suit for partition claiming her share and separate possession of the same.