How can we dismiss a partition suit against my father?

I have a partition suit pending in the lower court of West Bengal against my father. The suit was filed by my uncle and his son, regarding a property gifted to my father by my grandmother. The partition suit also includes other properties, which may or may not be legally partitionable. I have the original registered gift deed, tax receipt, and mutation record in my father's name. However, I do not have the original deed or any documents for the other properties included in the suit. How can I get this suit dismissed or at least have my father excluded from it?