What is ronin？
As the name suggests, ronin can actually mean wanderer. Samurai who lost their territory during the Meiji period had to wander around without a place to live. These samurai had no fixed lords, homes, wives, and lost their salaries, and lived a very downtrodden life. It could also be argued that they were once part of the hierarchical and privileged samurai, some people don't care to call them samurai, but it's like being a soldier except that a samurai who has a master is a regular army, while a ronin is at best a mercenary.
Can a ronin become a samurai again?
In fact, some ronin were hired by the lords on a temporary basis to do housekeeping or odd jobs, but Japan was unified during the time of Toyotomi Hideyoshi, and because of the relative stability of the society and the situation, the lords no longer needed to keep these ronin in captivity. Later on, when Tokugawa Ieyasu came to power, the power of the lords was hit again, and many of them were not as large or had as much income as before, and could not afford to maintain these people, so a new group of ronin was created.
At the end of the Edo period, the group of ronin grew larger and larger, and in order to survive, these people became politically active and sought to gain political advantage, and through the political changes of the time, the ronin existed for a long time. Later, with the disintegration of the samurai class, the unstable profession of ronin slowly disappeared from the stage of history. The samurai no longer existed, let alone the ronin.