Dear @Hassanali, 
Welcome to the Wefugees Community and thank you for reaching out to us. 
As holding a student residence permit doesn't "qualify" for a permanent residence permit (Niederlassungserlaubnis) in general and also doesn't "count" for the respective minimum years, I assume that he needs to hold the residence permit according to section 28 of the German Residence Act (as spouse of a German citizen) for at least three years before he can get the permanent status. 
Am I right on this dear @mbeon-fardeen? 
All the best, 
Meike