Hi Aarav_96,
Looking on both phones specifications, Sony Xperia Z3 is better in terms of camera.
CAMERA OF Z3 : 20megapixels
CAMERA OF C4: 13megapixels
Comparing both phones RAM. Z3 is still better it has a 3GB ram while compared to the C4 it has a 2GB ram.
For me, I'd choose Z3. Hope this helps!