The sensitivities of isospin asymmetry and collision geometry dependencies of
participant (overlapping region)- spectator (quasiprojectile and quasitarget
region) matter towards the symmetry energy using the isospin quantum molecular
dynamical model are explored. Particularly, the difference of the number of
nucleons in the overlapping zone to the quasi-projectile-target matter is found
to be quite sensitive to the symmetry energy at semiperipheral geometries
compared to the individual yield. It gives us a clue that this quantity can be
used as a measure of isospin migration. Further, the yield of neutrons (charge
of the second-largest fragment) is provided as a tool for overlapping region
(quasi-projectile-target) matter to check the sensitivity of the
above-mentioned observable towards the symmetry energy experimentally