  This paper uses the gravitational decoupling through the minimal geometric
deformation approach and extends a known isotropic solution for a
self-gravitating interior to two types of anisotropic spherical solutions in
Rastall gravity in the presence of electromagnetic field. By deforming only the
radial metric component, the field equations are decoupled into two sets, the
first of which corresponds to an isotropic distribution of matter while the
second set contains the anisotropic source. We obtain a solution of the first
set by employing the charged isotropic Finch-Skea ansatz, whereas a solution
for the second set is obtained by adopting two mimic constraints on the
pressure and density. The matching conditions at the stellar surface are
explored with the exterior geometry given by the deformed
Reissner-Nordstr$\ddot{o}$m spacetime. For the two fixed values of the Rastall
and charge parameters, we investigate physical features of both solutions
through graphical analysis of the energy conditions, equation of state
parameters, surface redshift and compactness function. The stability of both
solutions is also studied through the Herrera cracking approach and causality
condition. We deduce that while both solutions are physically viable, only the
solution corresponding to the pressure-like constraint is stable.
