@ jitesh
the way u used for normal molecule to find out the hybridisation , that is valid for isoelectronic species ,
isoelectronics species only have same bond order , thats it .. nothing else is diff . here and they behave like the same normal molecules .
and remember – IF ITS GIVEN ISOSTRUCTURAL SPECIES , then they both have same hybridisation with each other .
HOPE IT CLEARS NOW