The complex $[Co(en)_2Cl_2]Cl$ contains the complex cation $[Co(en)_2Cl_2]^+$. This complex ion exhibits both geometrical and optical isomerism.

1. Geometrical Isomerism: It can exist in cis and trans spatial arrangements.
2. Optical Isomerism: The trans-isomer possesses a plane of symmetry and is thus optically inactive (achiral). However, the cis-isomer lacks a plane of symmetry and is optically active, existing as a pair of non-superimposable mirror images (dextro and laevo enantiomers). Therefore, the total number of possible stereoisomers is 3 (one trans isomer and two enantiomeric cis isomers).