What is the legal ruling in Islamic law regarding prioritizing men over women in the funeral prayer and burial at the cemetery in cases of mass death?

The best approach is to pray a single congregational prayer over multiple جنائز (funerals) to ensure expediency and lightness. In this arrangement, men should be positioned closest to the Imam, followed by boys, and then women. Prioritizing the prayer for the most virtuous deceased (أفضل) is preferable when each جنازة is prayed over individually.

Regarding burial: If it is possible to bury each deceased separately, that is the desired approach. If not, then the one whose body is feared to change (deteriorate) should be prioritized, or the one who arrived earlier, or lots should be drawn among them. In cases of necessity requiring the burial of two bodies in one grave, the male should be placed before the female and positioned towards the Qibla, unless the female was placed first, in which case she should not be moved.