NOTE: I have replaced Djinn with Baskin

6 Sequels
The Texas Chainsaw Massacre 2 (1986)
Evil Dead 2 (1987)
Army of Darkness (1992)
Scream 2 (1997)
A Nightmare on Elm Street Part 3: Dream Warriors (1987)
Psycho II (1983)

6 countries
France: Diabolique (1955)
Turkey: Baskin (2015)
UK: Lifeforce (1985)
Canada: Videodrome (1983)
Poland: Demon (2015)
Spain: The Orphanage (2007)

6 decades
50's: Diabolique (1955)
60's: Psycho (1960)
70's: Dawn of the Dead (1978)
80's: Lifeforce (1985)
90's: Army of Darkness (1992)
00's: The Orphanage (2007)

6 films from before 1970
Diabolique (1955)
The Invisible Man (1933)
Dracula (1931)
Psycho (1960)
Quatermass and the Pit (1967)
The Blob (1958)

6 films from the following:
Carpenter: Prince of Darkness (1987)
Whale: The Invisible Man (1933)
Browning: Dracula (1931)
Craven: Scream 2 (1997)
Tom Holland: Fright Night (1985)
Raimi: Evil Dead (1981)

3 people eating people (non-zombie)
Raw (2016)
Ravenous (1999)
The Hills Have Eyes (2006)

1 Hammer Film
Quatermass and the Pit (1967)

1 Romero Dead film
Dawn of the Dead (1978)

1 terrible oversight:
Psycho (1960)

And 2 Tobe Hooper Films
Djinn (2013)
Lifeforce (1985)

Additional:
Poltergeist (1982)
Jacob's Ladder (1990)
The Devil's Backbone (2001)
Interview With A Vampire (1994)
In The Mouth of Madness (1994)
Blood Diner (1987)
The Skin I Live In (2011)