Gogeta, one of Dragon Ball's strongest, is the Metamoran fusion of Goku and Vegeta that was introduced to us canonically during Dragon Ball Super: Broly. Being a fusion, this form increases their power level tremendously, as seen in the movie, where they were easily able to fight Broly and overpower him.
Although Gogeta is pretty strong, some would argue unstoppable, there are certain characters we've already seen who are much stronger than him. To beat them, Gogeta would need to get stronger. Here are 5 characters from Dragon Ball that Gogeta can defeat, and 5 others that he can't.
10 Can Defeat: Toppo
One of the members of the Pride Troopers from Universe 11, Toppo is an extremely powerful fighter who is also in the running for becoming the next God of Destruction of his universe after Belmod.
Toppo's strength is quite immense and he was able to hold his own against Super Saiyan Blue Vegeta, which says a lot about how terrifying he is. His God of Destruction powers are another threat to nearly anyone who fights him. Despite that, Toppo's strength pales in comparison to Vegeta, so for Gogeta, defeating him shouldn't be difficult at all.
9 Can't Defeat: Beerus
Beerus is the God of Destruction of Universe 7 and someone whose powers far surpass that of Goku and Vegeta's. He was able to defeat Goku even in his Super Saiyan God form and wasn't even using half of his powers at the time.
Although Goku implied that Broly could be stronger than Beerus, he has never seen Beerus at full power, so going off of the statement would be highly inaccurate. Furthermore, Beerus has moves like Hakai up his sleeve, making his victory against Gogeta even more plausible.
8 Can Defeat: Broly
Quite possibly the strongest Saiyan to date, Broly was the main antagonist of Dragon Ball Super: Broly where he fought against Goku and Vegeta on his father's commands. Although he doesn't have control over his powers yet, Broly is incredibly strong as he had no trouble in overpowering both Goku and Vegeta together.
However, the two soon fused to become Gogeta and became strong enough to beat Broly without much trouble. Even then, it must be noted that Broly was able to push Gogeta to Super Saiyan Blue, which is a feat in itself.
7 Can't Defeat: Champa
Another God of Destruction, Champa is the brother of Beerus and sees over Universe 6 in a similar fashion to how Beerus does it in Universe 7. Champa's full powers haven't been revealed but he's likely comparable to Beerus himself, which means that defeating him certainly isn't easy.
In an all-out battle against Gogeta, it is difficult to see Champa lose simply because the powers of a God of Destruction are too dangerous for anyone to come up against. Champa may look physically weaker, but he shouldn't be underestimated.
6 Can Defeat: Freeza
Freeza is one of the biggest evil forces in Universe 7 who was recently brought back to life after the events of the Tournament of Power. He's continued to grow in strength, just like every other main character in the series and in his golden form, he's certainly a force to be reckoned with.
It is arguable if he can take down Goku or Vegeta in a fight as he is now, but defeating Gogeta is a different thing altogether. Freeza struggled to inflict even a single injury on Broly while Gogeta absolutely dominated Broly when they fought. That's enough proof that Freeza can't stand his ground against Gogeta.
5 Can't Defeat: Whis
Whis is one of the Angels in the world of Dragon Ball and his powers are said to be even greater than a God of Destruction's, scary as that may sound. Even though Gogeta is extremely powerful, it isn't possible for him to win against Whis, even if he gets stronger during the battle.
It must be noted that Whis is also a master of Ultra Instinct, which makes it hard for Gogeta to even land a blow on him, let alone defeat him in a fight. We're certain that there's no competition between the two.
4 Can Defeat: Gohan
Gohan is one of the strongest characters in the world of Dragon Ball even though he is a shadow of what he used to be. After the Tournament of Power, Gohan resolved to train once again in order to get strong enough to protect those close to him.
However, even if he has become stronger, it isn't possible for Gohan to win against Gogeta in a fight. We doubt Gogeta would even need to push himself to Super Saiyan to defeat Gohan, let alone Super Saiyan Blue.
3 Can't Defeat: Jiren
Jiren is one of the strongest characters in Dragon Ball, quite possibly the strongest mortal in existence right now. He's said to be stronger than Belmod, the God of Destruction of his Universe, which paints his powers to be something truly majestic.
Jiren was able to fight against Mastered Ultra Instinct Goku during the Tournament of Power, and he even held his own against him, meaning he should be able to do the same against Gogeta. Furthermore, Jiren got gradually stronger as the two fought and it's possible for him to do the same against Gogeta as well.
2 Can Defeat: Hit
Hit is an assassin from Universe 6 and possibly the most efficient one at that. Having already fought against the likes of Goku and Jiren, we've seen what he's capable of. Hit has the ability to skip time and even store the time that he's skipped to create his own little pocket dimension.
However, against overwhelming power, Hit's ability is useless, as seen when he clashed against Jiren. In a fight against Gogeta, we're certain that Hit won't fare too well.
1 Can't Defeat: Daishinkan
The Grand Priest, also known as the Daishinkan, is possibly the strongest character in the entire Dragon Ball series (not including Zen-oh). He's even stronger than the Angels, however, a glimpse of his strength is yet to be seen.
Despite that, we're fairly confident that Gogeta isn't even a significant threat to the Grand Priest the way he is now. To achieve that, both Goku and Vegeta would have to undergo severe training and get tens of times stronger, maybe even more.