6 sequels (mix-and-match. 6 total): Diary of the Dead, Survival of the Dead, Boogeyman 2, The Conjuring 2, Rec 2, Purge 2, Frankenstein Meets the Wolf Man, House of Frankenstein
6 countries: Cannibal Ferox = Italy; Macabre = Indonesia; The Babadook = Australia/Canada; Rec 2 = Spain; Kuroneko = Japan; Saint Martyrs des Damnés = Canada; The rest = USA/UK
6 decades: 20's to 00's
6 films from before 1970: The Haunting, Frankenstein Meets the Wolf Man, House of Frankenstein, The Invisible Man, The Unknown, The Mummy, Kuroneko
6 films from the following:
Carpenter: Vampires;
Raimi: Drag Me to Hell;
Whale: Invisible Man;
Browning: The Unknown;
Craven: People Under the Stairs
Tom Holland: Fright Night
3 people eating people (non-zombie): Cannibal Ferox, Eating Raoul, Macabre
1 Hammer Film: The Mummy
1 Romero Dead film: Diary of the Dead, Survival of the Dead
1 terrible oversight (use the following link, filter out the films you've seen and picked the highest rated film from the list that you can get ahold of) letterboxd.com/films/genre/horror/by/rating/size/small/:
Get Out

And 2 Tobe Hooper Films (There must ALWAYS be a Hooper film): Eaten Alive & The Damned Thing

WATCH THE ORIGINAL AND REMAKE OF IT.