8 Teacher,can you clarify 3/10 years bar?

8 teacher, can you pls clarify 3/10 years bar?

I heard some said if you stay over 6 months illegally, but less than 1 year, then it is 10 years bar; if stay less than 6 months, it is 3 years bar.

I searched web, some also said if stay less than 1 year illegally, it is 3 year bar, if it is more than 1 year, then 10 years bar.

which one is correct? when is the cut off time?

Thanks very much!