Can Mongolian students receive secondary education first?

Of course. According to official website, the People's Government of Wuhai City, the enrollment plan of Mengzhong (Wuhai Mongolian Middle School) is that Mongolians and other ethnic minorities among the fresh graduates of the sixth grade in the whole region can give priority to applying for attending Wuhai Mongolian Middle School, and school-age teenagers living in Haibowan District can choose to study in Mengzhong independently. Wuhai Mongolian Middle School is the only window school with ethnic characteristics in Wuhai, Inner Mongolia.