The first step is to find the quantity of electricity, in Coulombs, to discharge
Once we know this we can find the time this will take since we are told the current, which is the rate of flow of charge.
Nickel(II) ions are discharged:
We can find the charge on 1 mole of electrons by multiplying the electronic charge by the Avogadro Constant. This gives
Electric current is the rate of flow of charge:
In reality a current of this size, as well as being very dangerous, would not give a very good result.
The quality of the deposit at the cathode is favoured by a low current density which is current/area. So a low current over a high area gives a deposit that binds well to the surface.
A high current density like this would give a very spongy deposit which would fall off the cathode very easily.