Inheritance law

Salamalaikum, I wanted consultation regarding power of attorney I signed after my father’s death many years ago.
I came back from overseas last year and found out that my mother has sold everything. We had agreed verbally on selling one part of land and keep the rest of it but my mother did not even consult me or told me she is selling all of it.
She says that the buyers will give money slowly but whenever I ask her to show me the paperwork to see who bought it and for how much they bought it for she refuses and says I don’t have any kind of paperwork.
She refuses to give me my father’s death certificate and the copy of the power of attorney.
Something is not right and she says all my father’s property will be divided three equal ways, one part my mother one my sister and one for me although my father did not leave a will.
She also gave a small portion to our servant who she says now is her son and was adopted by my father which is not true.
Can you help me get my legal share according to the inheritance law of Pakistan.