Local shearless curves were found using a twist symplectic map. This map describes the toroidal evolution of the magnetic field lines in tokamaks. In this work, we employed the parameters of the TCABR (Tokamak Chauffage Alfvén Brésilien). We found that when there are two perturbative resonant modes acting on the same magnetic surface, local shearless curves may appear. The results we present were obtained by using the internal winding number for the perturbation on the magnetic field produced by a set of magnetic coils, the ergodic magnetic limiter.