Can partition suit be challenged after decree?

My father was the plaintiff in partition suit against my two uncle. In that case the schedule of property was 20 khattas in the described plaint. But the 4 kattas was sold jointly by my father and one uncle before 17 years from earlier of partition suit.so the physically total property is 16 kattas. But that was not mentioned in that case. Similarly the defendant did not arise this issue as he had the knowledge of sale. during the pendency of the suit both of my father and uncle passed away. after that me and my cousin are substitute plaintiffs and defendant respectively. I also mistakely not mentioned the sale details in that case.. repeatedly the next deffendent does not arise the issu..after all of this I got expartee preliminary decree over 20 katthas and got appointment of advocate commissioner. the advocate commissioner has confirmed his report before court on 16 kathhas.1)now the deffendent can arise this issues in partition suit? 2)the commissioner report may be canceled 3) thecase maybe dismissed?