Sure. Gotham is based on comics. It uses the comic backdrop to create a gritty and compelling TV series, while still maintaining some core comic elements and concepts.
The Gotham TV show doesn't follow the comics completely. It borrows the basic setting and some characters, but the plot and character arcs often differ significantly.
The 'Gotham series tie in novels' are special because they expand the universe. They can show things that couldn't be shown in the TV show due to time or budget constraints, like the backstories of minor characters.
Batman is one of the main characters. He is a vigilante who protects Gotham City from various threats. His skills in combat, detective work, and his array of high - tech gadgets make him a formidable force.
In the 'gotham original story', Bruce Wayne's parents are likely main characters as their murder is a huge part of Gotham's history. Also, perhaps the founders of Gotham, if they are named in the story, would be main characters.
Batman is surely one of the main characters. He is the dark knight who protects Gotham. Also, the Joker is likely to be there as his archnemesis. Commissioner Gordon, who works with Batman to keep the city in order, would probably be a main character too.