Many gated societies do allow common pets like dogs and cats, sometimes with a size or breed limit set by the society's own rules, while some owners simply prefer not to let their flat to a pet owner. This is agreed case by case, flat by flat. Tell the landlord about your pet before you sign, and get the permission written into the agreement so it cannot be withdrawn later.
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Sources
No outside source: this is how the practice works, in words, with nothing to cite.