Here are the studio names and who has the legal rights to which characters: (No copyright infringement intended. If there is any, I just got this from screenrant.com)
20th Century Fox
Daredevil: Daredevil/Matt Murdock, Elektra (Natchios), The Kingpin/Wilson Fisk, Bullseye, Jack Murdock, Karen Page, Ben Urich
Elektra: Christine Cord/Tatoo, Typhoid Mary/Marry Alice Walker, Kirigi, Stick, Stone
Fantastic Four: Doctor Doom/Victor von Doom, Human Torch/Johnny Storm, Invisible Woman/Susan Storm, Mr. Fantastic/Dr. Reed Richards, The Thing/Ben Grimm, Nova/Frankie Raye, Alicia Masters, Willie Lumpkin
X-Men Mutants: [Agent Zero/Maverick/David North], Angel/Warren Worthington III, Arclight/Phillippa Sontag, Beast/Dr. Henry Phillip “Hank” McCoy, [Blob/Frederick J. Dukes], [Bolt/Christopher Bradley], Callisto, Colossus/Piotr Nikolaievitch Rasputin, Cyclops/Scott Summers, [Deadpool/Wade Wilson], Emma (Grace) Frost, Jean Grey/Phoenix, Juggernaut/Cain Marko, Gambit/Remy LeBeau, Glob Herman/Herman Gardner, Iceman/Bobby Drake, Jubilee/Jubilation Lee, Katherine “Kitty” Anne Pryde, [Kestrel/John Wraith], Lady Deathstrike/Yuriko Oyama, Leech, Magneto/Erik Magnus Lehnsherr, Mastermind/Jason (Wyngarde), Multiple Man/James Arthur Madrox, Mystique/Raven Darkholme, Nightcrawler/Kurt Wagner, Phat/William Robert “Billy-Bob” Reilly, Professor Charles Xavier, Psylocke/Elizabeth “Betsy” Braddock, Pyro/St. John Allerdyce, Quill/Max Jordan, Rogue/(Anna) Marie, Sabretooth/Victor Creed, Sebastian Hiram Shaw, [Silver Fox], Siryn/Theresa Rourke Cassidy, (The) Spike, Storm/Ororo Munroe, Wolverine/Logan
X-Men Non-Mutants: Drake Family (Steven, Madeline, Ronny), Grey Family (Dr. John, Elaine), Henry Peter Gyrich, Robert Edward Kelly, Dr. Moira Kinross MacTaggert, Dr. Kavita Rao, William Stryker, Bolivar Trask, Warren Worthington II
New Line Cinema
Vampires: Blade, Deacon Frost, Dracula/Vlad Tepes
Non-Vampires: Hannibal King, Abraham Whistler
Sony Pictures
Ghost Rider: Ghost Rider/Johnny Blaze, Blackheart/Legion, Phantom Rider/Carter Slade, Abigor, Gressil, Mephistopheles, Wallow, Barton Blaze, Roxanne Simpson
Spider-Man: Spider-Man/Peter Parker, Doctor Octopus/Otto Octavius, Green Goblin/Norman Osborn, (New) Green Goblin/Harry Osborn, [The Lizard]/Dr. Curt Connors, Sandman/Flint Marko, Venom/Eddie Brock Jr., Betty Brant, Dennis Carradine (Buglar), J. Jonah Jameson, Ben Parker, May Parker, John Jameson, Joseph “Robbie” Robertson, Gwen Stacy, Mendel Stromm, Flash Thompson
Lionsgate Entertainment
Punisher: The Punisher/Frank Castle, Jigsaw/Billy Russoti, Microchip/Linus Liberman, Joan the Mouse, Maginty, Mr. Bumpo, Spacker Dave, The Russian, Maria Elizabeth Castle, Detective Martin Soap,
(There wasn't one for Marvel so I'm gonna go from memory)
Thor and other related characters
Captain America and other related characters
Iron Man and other related characters
Dr. Strange
And others which I hope you'll tell me!