A junior recruiter position is an entry-level position. You may not have direct recruitment experience but you may have some level of experience in human resources; even if it is in an intern capacity. A degree in human resources will be a huge plus, as will a human resources technical skill set.
You will most likely be working under the guidance of a more senior recruiter and may be tasked with assisting them with their more mundane tasks. In time, you will be entrusted to complete the entire recruitment process for a vacant position on your own.