mature/rad-dimension alu, which size allowed? and how?

hello people. have absolutely no idea in the area. and please answer my question regarding the Austrian right. I bought with my used car, 4 tyres with enzo alu rims. enzo-rad type h 15″. the tyres mounted on it are 195/60/15″. on my car, however, can only mature with 175/70R14 (acc. to registration) be mounted. I can now not use the tyres because they are too wide, OR? (i.e. my previous owner has made this legal again). I do to be able to mount them anyway and how much does that cost? many thanks for your help uj ps: car data: subaru impreza BJ00 type/variant: GC/GF, kombi, 1,6 (70kw)