Generally speaking, soldiers who just went to college are relatively young, which has a vital age advantage for entering military schools! You can apply for military school after serving 1 year.
The conditions for entering a military school are: having a high school education or equivalent, having served in active service for more than 1 year and less than 3 years, and being under 22 years old (as of June 1 day of that year). If you are a soldier of ethnic minorities or a college student enlisted in an ordinary university, the age can be relaxed by 1 year.