Studying in China from HK with HKSAR Re-entry Permit

I hold a French passport + HK permanent ID + HKSAR Re-entry Permit.

I will enter mainland from Hong Kong with my HKSAR Re-entry Permit. Can I stay more than 4 months with this Permit? I don't know what's the rule with this Permit.

Or will I need the Student X2 type to study in mainland for 4 months?

Thank you for your help