From bounty hunters to assassins, The Book of Boba Fett is filled with some of Star Wars' deadliest killers who continue to survive against all odds. If these characters were thrown into an arena for the Hunger Games, it would make for a truly competitive and brutal event.
If this scenario follows the rules of the Hunger Games as seen in the books and movies, The Book of Boba Fett characters are not allowed to bring any of their own weapons or armor into the arena. This means Din Djarin could not bring in the Darksaber and neither he nor Boba Fett could bring in their armor, thus changing which of these Star Wars characters would have the advantage.
Mayor Mok Shaiz's Majordomo
Mayor Mok Shaiz's obsequious Majordomo is excellent at talking and commits to what he's saying, even when the party listening to him does not like what they're hearing. However, he ranks as The Book of Boba Fett's least brave character, and would not fare well in a ruthless Hunger Games environment.
When Boba Fett and Fennec Shand go to confront him and Mayor Mok Shaiz in the third episode, the Majordomo almost immediately flees and his escape attempt is a short-lived, bumbling mess as he does not get far in his speeder and crashes into a cart of meilooruns. He has no fighting prowess and lacks the survival instincts and courage needed to survive in the arena.
8D8
While 8D8 probably couldn't win the Hunger Games, he could prove to be a great ally. In The Book of Boba Fett, he has shared a great deal of valuable information about the politics of Mos Espa and is able to translate what species like the Aqualish are saying. He could help other tributes communicate with each other.
8D8 also understands the mindset of Mos Espa's people and what they will best respond to. He understands the need to instill fear and has even done this himself by torturing droids. Against other individuals like Fennec Shand or Black Krrsantan, 8D8 likely would not last very long, but he does have enough skills and knowledge that would make some of the tributes keep him around for a while.
Garsa Fwip
The diversity of clientele that frequent the Sanctuary shows that Garsa Fwip knows how to create and maintain an establishment that all manner of individuals can enjoy. Musicians like Max Rebo and other Twi'leks happily work there. From Wookies and Trandoshans to retired bounty hunters like Karales (played by Big Brother legend Dr. Will Kirby), all kinds of individuals choose to be patrons there.
Garsa knows how to make people happy and would be able to help form and maintain alliances in the Hunger Games. She's never shown any ability to fight though, and was ultimately unable to protect the Sanctuary from the Pykes. She would be a good member of an alliance, but would not be able to go toe-to-toe in combat against bounty hunters and assassins.
Din Djarin
Din Djarin has proven to be a formidable Mandalorian who has bested all manner of opponents. His prowess with weapons and his experience would make him a daunting tribute to face in the arena.
However, Din is used to fighting with his Mandalorian armor and with weapons like his blaster, whistling birds, a Beskar spear, and most recently, the Darksaber. Adapting to new weapons probably wouldn't be too challenging for him, but fighting without his armor would feel completely foreign and put him out of his depth, overall weakening his chances in the Games.
The Tusken Warrior
The Tusken Warrior is a skilled fighter. She is an expert at wielding the gaffi stick--the traditional weapon of the Tuskens--and teaches Boba Fett how to wield the weapon effectively. Her ability to communicate, learn to trust, and teach Boba bodes well for an alliance in the Hunger Games.
During the train heist, even the heavily armed Pykes were no match for the Tusken Warrior. She is just as strong a fighter as any of the other tributes. The one thing that would greatly impact the Tusken Warrior's chances of winning the Hunger Games is the environment that is chosen for the arena. Tuskens are native to Tatooine and only know the desert environment. Most of the other tributes are used to a variety of climates and conditions when fighting for survival, but an arena environment other than the desert is something that the Tusken Warrior has never faced before.
Black Krrsantan
Black Krrsantan would have the greatest physical strength and ferocity out of all these tributes. With experience fighting as a gladiator, Black Krrsantan has been trained to fight to the death for spectacle, which gives him an enormous advantage over everyone. Despite these undeniable strengths, Black Krrsantan lacks some of the traits that are helpful to going far in the Games, especially when considering that they are more than a straightforward gladiator match.
Black Krrsantan lacks patience and can act impulsively, such as when he attacked the Trandoshans in the Sanctuary. In order to make it all the way through, tributes often need patience and to not make rash decisions, both of which Black Krrsantan would struggle with. Also, for all of his ferocity and physical strength, he is not invincible, especially when others band together to defeat him. Boba Fett, Fennec Shand, the Gamorrean guards, and the Mods were all able to work together to force him into the rancor pit. Against a unified alliance, even Black Krrsantan couldn't make it all the way on his own.
Cad Bane
Cad Bane is a ruthless bounty hunter who has no moral qualms about doing whatever is necessary to get the job done. He's kidnapped Force-sensitive children for Darth Sidious, kidnapped The Bad Batch's best character Omega for the Kaminoans, blown up his own droid Todo 360 as part of a job, and now he's shot to kill Cobb Vanth and his deputy for the Pykes.
This ruthlessness would serve him well in the Hunger Games, as he wouldn't hesitate twice before killing or betraying any of the other tributes. The typical weaponry in the Games might prove to be a challenge for him though, as he is used to blasters and the weapons in the Games are usually more along the lines of swords, spears, and bow and arrows.
Boba Fett
There is a good reason why Boba Fett has a reputation for being one of the galaxy's most feared bounty hunters. Boba has also proven that he does not need his Mandalorian armor to be brutal and get the job done. Using nothing but chains and his physical strength, he killed the six-limbed monster that emerged from beneath the sands of Tatooine in The Book of Boba Fett's first episode. He's also taken down Pykes, Niktos, and Stormtroopers with just his gaffi stick. No matter what kind of weapon or protection he gets his hands on in the arena, Boba will be able to use whatever resources he has to kill his opponents.
His time in the Sarlacc took its toll on him and he is sometimes more vulnerable than he used to be--such as when he was attacked by the Order of the Night Wind and needed to immediately get back into the bacta pod--but he is also wiser than he used to be and can still be the lethal and menacing Boba Fett when need be.
Fennec Shand
As a Master Assassin, Fennec Shand knows how to kill better than anyone. She can take out a target from far away with a rifle, but she's just as adept with a regular blaster or any manner of blade. She's already outsmarted and defeated some of her strongest competition in the past, such as Cad Bane in The Bad Batch.
Fennec is individually a strong tribute, but her ability to form strong alliances and work well with other characters in The Mandalorian and The Book of Boba Fett also shows that she would make an excellent ally in the Games. Fennec has the best shot of winning because she has the ultimate combination of deadliness, strength, intelligence, and the ability to forge and maintain powerful alliances.