It's hard to give an exact time as it depends on the manga's plot development. But typically, Yuta Okkotsu shows up when certain events and character arcs lead to his introduction.
Naruto's animation was related to the manga. In animation production, there would sometimes be some changes to the manga plot, especially in terms of character setting, plot development, and plot twists. For example, in the 69th episode of Naruto, Kishimoto made changes and supplements to the plot of the manga so that the audience could better understand the development of the story.
The question of whether the animation plot would be the same as the manga plot could not be answered with certainty. Although Naruto and anime had different storylines and character settings, there were some similarities between the two. For example, the important characters in Naruto had unique skills and abilities. Their battles and storylines were often related to background stories and historical events. Therefore, in the animation production, the storyline might be adapted and adjusted to meet the audience's taste and market demand while retaining the characteristics of the manga.