Hi, according to Kushanshah, but only to say that the symbol seems to be a -staurogram- (greek letters tau -T- and rho -P-) that represents Jesus on the cross. The Christogram represents the name of Christ (letters Chi -X- and Rho -P-).
It is not only for more accurate description but for with staurogram we can reduce the possible mints to Rome, Aquileia, Tesaloniki and Cyzicvs (cheking "La moneda del Bajo Imperio Romano" Eladio Gutierrez Casaos, 2008), although for this coin we can,t read its mint.