Is it permissible to read inside graveyards, and does the deceased benefit from the reading of their relative?

Reading the Quran at graves is not from the Sunnah. Rather, habitually doing so is an innovation (bid'ah) that none of the reputable scholars, such as Ibn Taymiyyah and Ibn 'Uthaymeen, have permitted. Reading at graves does not benefit the deceased, as the fundamental principle regarding acts of worship is tawqif (to be based on revealed texts). Nothing reaches the deceased except what the Sunnah indicates will reach them, such as charity and making up missed obligations. Some scholars are of the view that the reward of any act of obedience reaches the deceased if it is intended for them. Supplicating for the deceased is better, as it is superior to dedicating good deeds to them. The fatwa issued is that the deceased benefits from what a Muslim dedicates to them, whether it be from reading the Quran or other acts of obedience, provided the Muslim performs these acts and supplicates to Allah to make their reward for the deceased.