In many fanfictions, Naruto might use his unique chakra, perhaps enhanced by his Uzumaki heritage or the Nine - Tails' power. His strong will and connection to his friends could also play a role, allowing him to find a way to break the seal through sheer determination and his belief in Neji's potential.
In some fanfictions, Naruto might use his new jutsu skills that he's developed in secret training. He could surprise Neji with a powerful Rasengan variant, overpowering him and rescuing Hinata.
Well, Naruto could use his shadow clone technique. He'd create multiple clones to surround Hinata and keep Neji at bay. Naruto has a strong sense of justice and cares deeply for Hinata, so he'd do whatever it takes. He might also try to talk Neji down, appealing to their shared experiences and values, while positioning himself between Neji and Hinata to block any potential physical attacks.
Naruto's character could develop in terms of his leadership skills. When he saves Neji, he has to take charge of the situation, making quick decisions on how to deal with the threat to Neji. This would show his growth from the impulsive boy to a more responsible leader. He might also develop more empathy as he realizes the pain and danger Neji is in, which further deepens his bond with his comrades.