Does the defendant have a right to add parties to the partition suit?

There are 8 children for Ramappa, 5 male members and 3 female members, One of the male member files a partition suit in 2008 against mother and 4 brothers , intentionally leaving 3 sisters. Suit is still pending. One of the sister filed impleading application in 2024 and got impleaded as defendant no. 6. Still 2 sisters are left out. Without their signature, I being the defendant no. 6 , can I file impleading application requesting court to add 2 left out sisiters? My advocate is saying I cant file that application without their signatures because i am a defendant in the suit, only plaintiff has a power to add them but Plaintiff will not add them because he does not want to give share to his sisters. Please suggest me what to be done.