Olych – to clarify, an Annual General Meeting (AGM) is just a General Meeting that the NSW Strata Schemes Management Act (SCMA) states must be held once a year, at a time that’s one (1) month either side of the date that the first ever General Meeting was held.
All General Meetings held at other times are called Extraordinary General Meetings (EGM), are voluntary, are are convened either by a vote of the Executive Committee or at the written request of Owners whose Lots together represent at least 25% of the aggregate units of entitlement (UOE) for the Plan.
So in specific response to your question, if you want to amend or rescind a decision taken at an AGM you can either:
1) Place a Motion to do that on the Agenda for the next AGM; OR
2) Ask Member/s of your Executive Committee to convene an EGM so that you can place your Motion on the Agenda for that Meeting; OR
3) Seek the support of sufficient other Owners whose Lots have UOE totaling at least 25% of the aggregate for your Plan, and have them sign a “petition” calling upon your E/C Secretary to convene an EGM so that you can place your Motion on the Agenda for that Meeting ; OR
4) Apply to the NSW Civil and Administrative Tribunal (NCAT) for Orders to invalidate whatever decision/s of the AGM you have issue with. You must have valid reasons though, such as that you have been adversely affected by the Meeting’s decision, or that the decision only passed the vote because the Meeting was not held properly.
A little complicated, but I hope this helps!