How can one deal with the injustice inflicted upon them by their family in the distribution of inheritance, and relinquish their right, while maintaining family relations, especially during Eids?

It is not permissible to favor some children over others in gifts unless there is a legitimate reason. Examples of this include one of them having many dependents, being a student of knowledge, or being ill. However, if this giving is contingent upon the father's death, it is a will that is not permissible for an heir. The siblings who were favored with the gift must return the excess beyond their right to their siblings, and they must advise their father. It is not permissible to abandon parents due to a lack of justice.