Is the Hyundai i10 bumper plastic or metal?

plastic........................

Nowadays, most cars are made of plastic, mainly due to weight reduction, excellent corrosion resistance, flexibility, and durability. Thus, my guess is that your Hyundai i10's bumper is also tailored from high performance plastics.

If it's part of a Hyundai, it's probably plastic.

Bang your tooth on it. You'll be able to tell if it is metal.

The bumper is metal, what you see on the outside is plastic. That part is the bumper cover, not the bumper. 

Pretty much every modern mass produced car today has plastic bumpers, plastic or foam absorbers behind the bumpers to protect against small impacts, and finally a metal reinforcement bar to hold everything in place as well as act as the final absorber against larger impacts.

Plastic bumpers save weight as well as they can easily be formed/molded to fit tightly against the chassis for better aerodynamics and greater styling possibilities.