Hello, Greetings of the day!
For the query you posted, I would suggest that:
When you are in AGM and you are well aware that you have to pay maintenance charges but still, you have not paid the maintenance amount. So according to the rules of society, if it is mentioned to pay a penalty, so you have to pay the same for breach of terms and conditions.
If a flat-owner fails to pay his maintenance charges on time, the society can initiate legal proceedings to recover the said bill amounts. In such an application, the society shall request the Registrar to issue a certificate for the recovery of the amount against the defaulting member of the society.
Hope it helps