Can I revoke my uncle’s power under grandfather’s will?

My grandfather had three sons and daughters. At the age of 91, my father’s elder brother (XYZ) made my grandfather prepare a will, giving power to XYZ. The will stated that since my grandfather was getting old, he was appointing XYZ to distribute the properties equally. It also mentioned that XYZ had the right to keep or sell any part of the property as he wished. My father has passed away. However, XYZ is using that power to sell properties and keep the money for himself. When my uncle (my father's other brother) and I ask about it, he says he spent money on construction and repairs as mentioned in the will. The will was prepared between 1999 and 2000. After my grandfather passed away, my father had asked for an equal distribution, but XYZ refused and delayed the process. My grandfather had two wives. The first wife had no children, so during my father’s marriage, they wrote a note naming him as her legal heir ('varisu'). This note, which proves he is the third son and first wife's adopted heir, is still with XYZ but is unregistered. I am not enjoying any share as the adopted son of the first wife, neither 50% nor even one-third of the property. Since my father is no longer alive, can I revoke the power given to XYZ and claim what is rightfully mine?