Question

unit of electrostatic force​

Answer 1

newtons

Units. When the electromagnetic theory is expressed in the International System of Units, force is measured in newtons, charge in coulombs, and distance in meters. Coulomb's constant is given by ke = 14πε0.

Answer 2

newton(N) is the unit of electrostatic force.

Do remember no matter which type of force, all are dimensionally [ML^2T^-2]

and thus unit will be newton.

and not Newtons because n cant be in upper case and it cant be plural as s can also signify seconds.