The crime of stirring up trouble may be sentenced to public surveillance and criminal detention, and those with bad circumstances may be sentenced to fixed-term imprisonment.
Your friend should be controlled, and the legal period is 3-2 years. Surrender can be given a lighter or mitigated punishment.
About bail pending trial
Article 51 of the Criminal Procedure Law clearly stipulates that the people's courts, people's procuratorates and public security organs may obtain bail pending trial for criminal suspects and defendants under any of the following circumstances: (1) Those who may be sentenced to public surveillance, criminal detention or independently apply additional punishment; . . . (Other items omitted)
So your friend can get bail pending trial. Need his relatives to vouch for him, or pay 200 yuan/day deposit. The latter is more expensive, so it is recommended to take the former.
Article 52 of the Criminal Procedure Law clearly stipulates that criminal suspects, defendants, their legal representatives and close relatives in custody have the right to apply for bail pending trial. (Whether a criminal suspect or other defender can apply for bail pending trial is also inconsistent in judicial practice. Some places allow criminal suspects and other defenders to apply for bail pending trial, while others do not. )