Apple Mac Pro A1186 Power Cable
Apple's manuals are online: https://manuals.info.apple.com/MANUALS/1000/MA1639/en_US/mac_pro_mid2012_ug.pdf but they don't say IEC320C13 on Mac end.

In the US - you're looking for NEMA 5-15P to IEC320C13 like https://www.amazon.com/C2G-Cables-14719-Universal-IEC320C13/dp/B000067RTS

The MacPro are all standard cables, so get whatever wall configuration you have in your country for any PC with a standard power supply. Basically, any hardware or computer store will be able to hook you up since Mac power supplies are international in terms of 50/60 Hz and 110/220 VAC.