Could someone Identify this Insect Hive on my Balcony Grill
These are certainly paper wasps (Vespidae) building their paper nest. Looks like a species of Ropalidia, which are known from Singapore.

I know little about Ropalidia, it seems to be rather small and probably harmless, but our larger European wasps can sting and bite and are sometimes quite aggressive (this refers first of all to Vespula germanica).