Which of the following complex species does not obey EAN rule?

[Cr(NH₃)₆]³⁺

EAN is effective atomic number and it is represented as:

EAN = Z - (O.N) + 2(C.N) or number of lone pairs donated to central atom

where Z = atomic number

O.N. = oxidation number

C.N. = coordination number

In [Cr(NH₃)₆]³⁺ 

x + 6(0) = +3

x = 3

Cr³⁺ (Z = 24) 

EAN = 24 - 3 + 2(6) = 21 + 12 = 33