A Requiem Mass Is OK on Most Sundays
May we have Requiem Mass celebrated on Sunday?
Yes, with some restrictions. A requiem Mass is a Mass for the dead. It is a specific ritual Mass, as opposed to the Mass of the day being offered for someone's soul. It can either be the Rite of Christian Funeral Mass or a ritual Mass for the dead.
General Instruction of the Roman Missal:
380. Among the Masses for the Dead, the Funeral Mass holds first place. It may be celebrated on any day except for solemnities that are holy days of obligation, Holy Thursday, the Easter Triduum, and the Sundays of Advent, Lent, and Easter, with due regard also for all the other requirements of the norm of the law.
381. A Mass for the Dead may be celebrated on receiving the news of a death, for the final burial, or the first anniversary, even on days within the Octave of Christmas, on obligatory memorials, and on weekdays, except for Ash Wednesday or weekdays during Holy Week.