The isovector giant and Pygmy dipole resonances in even-even Ni isotopes are studied within the framework of a fully consistent relativistic random phase approximation built on the relativistic mean field ground state. An additional isoscalar-isovector nonlinear coupling term is adopted in the effective The isovector giant and Pygmy dipole resonances in even-even Ni isotopes are studied within the framework of a fully consistent relativistic random phase approximation built on the relativistic mean field ground state. An additional isoscalar-isovector nonlinear coupling term is adopted in the effective