Three marks of moha

Lobha: nicca, sukkha, attā

Dosa: nicca, dukkha, attā

Moha: nicca, na sukkha na dukkha(neutral feeling or uppekha or equinimity), attā

Is the above methodology right or wrong?

Everywhere in the suttas, Moha = nicca, sukha, attā.

As moha = irrational attention to a neutral object

Then why in the suttas 2nd mark of existence as sukha, instead of neut

ral one?

Yes it is. Simple logic dictates that if lobha, moha, etc were nicca, there would be no escape.

A better approach would be to read some basic intro texts or take an Intro course in the basics of Buddhism through this: https://buddhistuniversity.net/

:folded_hands:

Sorry, but real meaning here => not the permanence of moha, but instead the distortion of perception in moha for one with a lack of wisdom, i.e., an asuttva putthujana.
Three marks of existence:
Anicca, dukkha and anattā.