Huckel's rule is generally stated as that in order to be aromatic a molecule must have a certain number of electrons i.e bonds or lone pairs or lone pairs within p orbitals.
Also, the compounds must contain electrons to be aromatic, where and so on.
The ions that obey Huckel Rule:
All the ions which obey Huckel's rule are known to be aromatic in nature.
These ions must have electrons, to fulfill the condition of aromaticity.
Example: Cyclopentadienyl anion is aromatic as it has electrons, obeying the Huckels rule, for which the structure can be shown as
Hence, All the ions which are aromatic obey the Huckel rule.