One possible reason could be that the clan fears his power. In some fanfictions, Naruto's growing strength and his potential to disrupt the clan's traditional power structure might lead to his exile. They may see him as a threat to their established ways.
At first, Naruto might be shocked and confused. He would probably wonder why his own clan would do such a thing to him. He might feel a deep sense of betrayal, especially since he has always longed for a family and a sense of belonging within the Uzumaki clan. But being Naruto, he would soon turn his confusion and pain into determination. He would vow to prove himself and show the clan that they were wrong to exile him.
It could be due to a prophecy. The Uzumaki clan might have received a prophecy that Naruto would bring great turmoil or change to the clan, and rather than face the uncertainty, they chose to exile him. Some clans in the Naruto universe are very superstitious about prophecies. Also, Naruto's unruly nature as a child could have been misinterpreted. His pranks and disregard for some of the strict clan traditions might have been seen as disrespectful and a sign that he didn't belong in the Uzumaki clan, leading to his exile.
Well, in some fanfictions, Naruto might start by finding suitable partners within the village. Since he is the last of his clan, he could look for women who are willing to carry on the Uzumaki bloodline. He may also use his influence as a hero to encourage others to support his clan - revival efforts, like getting the village to provide resources for the new Uzumaki generation.
In this fanfiction, Naruto could reject his clan because of the dark secrets or past actions of the clan. He is a character who values justice and friendship. If the clan has a history of wrongdoings that he discovers, he may not want to be associated with it. Also, Naruto has his own dreams and goals that might not fit within the framework of the clan. He has always been a bit of a rebel, and rejecting the clan could be his way of standing up for what he believes in.
One possible reason could be to seek greater power and training opportunities elsewhere. Maybe he feels restricted within his clan in terms of the type of jutsu he can learn or the level of training he can receive. So, he decides to leave to explore different ninja arts and grow stronger on his own terms.
Naruto might recruit individuals who have unique talents that can contribute to the clan. For example, someone with exceptional medical ninjutsu skills could be a valuable addition. He may also look for those who have a great deal of loyalty and perseverance, as these are qualities he values highly. In addition, he could recruit those who have been ostracized or overlooked in the village, giving them a new family and purpose within his clan.
He could start by gathering like - minded individuals. Maybe those who share his ideals of hard work and perseverance, like some of the underdogs he befriended throughout his life in the original Naruto story.
First of all, Naruto would have to establish the clan's home base. In the fanfiction, it could be a hidden village within the existing Hidden Leaf Village or a secluded area outside. He would also need to decide on the clan's hierarchy. Who would be the leaders, the elders, and the regular members? Additionally, he would need to pass on his knowledge and skills to the new clan members, perhaps by creating a special training regime.
One challenge is the lack of pure - blood Uzumaki. Since he is the last one he knows of, finding suitable mates with enough Uzumaki blood could be difficult. Also, the Uzumaki clan has a lot of enemies. Those enemies might try to stop Naruto from reviving the clan so they don't become a threat again.