What is the ruling of Islamic law regarding a father allocating a plot of land to his daughters as their future inheritance, and regarding brothers disinheriting their sisters and seizing their mother's share under the pretext of caring for her, and threatening to sever family ties if they resort to legal action?

Resolving disputes falls within the jurisdiction of the Sharia courts, as they are best equipped to hear from all parties involved in a conflict. A Mufti, on the other hand, only hears from one party, and his opinion is for general guidance. Your right to your father's inheritance is established unless you willingly relinquish it. The land your father mentioned as your share must be returned to the inheritance and distributed among all heirs according to their legally prescribed shares, because it is considered a bequest to an heir, and there is no bequest to an heir unless the other heirs agree. Whoever does not waive their right must be given it. And whoever transgresses the limits of Allah and wrongfully consumes the property of others will face a severe torment.