Without having read 'the tenth man novel', it's difficult to name the main characters accurately. But we can make some educated guesses. The tenth man is surely a key character. There may be a mentor - like figure who guides the tenth man or a rival who competes with him for something. Additionally, there could be characters representing different aspects of the society or situation in which the story is set. These could all potentially be main characters, but to be certain, one would need to read the novel.
Since I haven't read the novel, I can't say for sure who the main characters are. But I assume the tenth man himself is a main character. There might also be others who interact with him closely, like the other nine in his group.
I don't know precisely who the main characters in 'the tenth man novel' are. However, if the title is anything to go by, the tenth man is likely to be a central figure. There could also be antagonists or supporting characters. For example, there might be a leader among the group of ten who clashes with the tenth man, or a friend who supports him. Without reading the book, it's hard to be more specific.