Do last will and testaments outweigh the rights of other beneficiaries?

Hi, Attorney! I bought a property for my parents. Our parents died. Our mother died last year. There is a Deed of Sale under my parents name. Last month my brother died and his surviving wife said our mother who was very ill made a last will and testament regarding the property that favors my late brother. My brother was very controlling and with bad temper and we are afraid that if the will really exists our mother signed it under duress or the document is forged. I have 5 living siblings. How can we transfer the property under our names? Which department to approach? Do Last Will and Testaments outweigh the rights of other children? Since the property is not divided yet to each kid when mother and our brother died, is my sister in law (married to my brother) entitled to the ownership of the house (built in the said lot property) that parents owned but my brother occupied for more than 10 years? Some of our siblings also built their houses in the same lot. Please help. We are afraid of my sister in law's relatives. They are harassing us day in and day out.

who has the title?

Thank you Atty. for your immediate and timely response.
My mother gave me the copy of the Transfer Certificate of Title. My mother's name is written as the sole owner of the property.

assuming you are all legitimate children, all the children inherit in equal shares if there is no will. your remedy is to file a petition for settlement of the estate. but you can begin with a letter to them demanding they produce this purported will, and when they show it to you, tell them the law reserves a portion for each child.

Where should I file the petition for settlement to the estate, Atty? Since my brother died before the settlement is done, is his surviving wife has the right to inherit his share?

such a petition is filed at the residence of the decedent.

Thank you for your reply Atty but I'm sorry I did not phrase my question clearly. I mean which branch of government should we file the settlement? Is it at Registry of Deeds?

with the RTC