What is the correct simplified character for Macau’s Taipa and Cotai?
There are no &quot;Simplified&quot; and &quot;Traditional&quot; versions of this character.
From Wikipedia:

澳門本地的「氹」（現代字）為異體字，古作「凼」、「窞」，數碼時代，由於內地字型中缺氹字，產生中國內地部份出版物顯示古字凼仔
The local character used in Macao,「氹」, is the modern version; in older times, it was written as「凼」and「窞」. In the digital age, due to Mainland China initially lacking support for the character「氹」, various publications substituted the character「氹」with the character「凼」instead.

The modern way to write it is「氹」.「凼」was used in the past, when the Mainland didn't encode the character in their digital standards.