c
The complex \(\left[\operatorname{Pt}\left(N H_{3}\right)_{2} C l_{2}\right], p t-C l\) has square planar geometry.
The isomer will be trans if the distance between two chlorine atoms is twice
the \(C - Cl\) bond length.

The isomer will be cis if the distance between two chlorine atoms is less than twice the \(C - Cl\) bond length. This is the case in the given complex as \(2.8 A<2 \times\) \(2 A\)
Thus the given complex is cis square planar complex.
Hence, the correct option is \(C\)