Quick answer
Submersible pumps need a cable built for the worst conditions — underwater, underground, in mud and constant wet. The standard choice is a flat multicore cable: its slim profile runs neatly down the bore alongside the pipe, and the construction resists water and abrasion.
APAR's Shakti Flat Multicore (copper) and AlumShakti Flat Multicore (aluminium, economical) are engineered for submersible pump motors. Size the cable to the motor and depth, and have an electrician confirm — see how to choose the right cable.