Dear Shilpa,
2/3rd are rotational directors and of which 1/3rd are to retire in every AGM and may be reappointed in that AGM.
Since, your Articles provide not to count MD and WTD for the purpose of retirement and hence only the balance directors shall be counted for the purpose of retirement.
Pratical Solution:
Total No of Directors: 6
WTD & MD: 2+1
Balance Directors: 6-3 =3
Rotational Directors: 2/3rd of the Balance i.e 3*2/3=2
Director to retire in this AGM: 1/3rd of rotational director i.e 2*1/3= 0.66 i.e 1
Note: In case the number is not 3 or in the multiple of 3 the number nearest to the one-third shall retire from office.
Now, I hope Your query is resolved.