A sign in the carpark. The temple-goers are largely Indian and Sri Lankan, so speak a variety of different languages which would be impracticable to individually transcribe on one sign. Of course, some visitors may also not speak any Indian or Sri Lankan language. Given that it is situated in Australia, simple English is the most universally understood option. This is especially important for a sign like this and the following one, which are rules, and therefore need to be understood even by “outsiders” to the temple.
This sign outside the temple has a similar purpose, so is also in English. “Thatchanai” is in Tamil, likely because it is an important cultural aspect of the temple proceedings, but it has an English definition following. Interestingly, “prasatham” (food offerings) doesn’t have an English definition although the general concept is evident from context. Perhaps the management expects that a newcomer to the temple may bring donations but only a regular temple-goer is likely to bring offerings, and that such a person is likely to be Tamil. “Thatchanai” is also part of fewer Indian and Sri Lankan languages than “prasatham” and therefore more likely to require an English explanation. Interestingly, both words use the Roman alphabet. I think this is likely for simplicity and elegance of formatting although it could be anglicised to be less confusing to non-Tamil speakers.
Once again, English is the language of the imperative. The slightly awkward phrasing might indicate that English is not the first language of the sign-writer.
This sign includes and prioritises Tamil, presumably because, as a source of Tamil books and classes, the school will have a higher proportion of Tamil visitors than the temple itself.
This sign also includes and prioritises Tamil. It is slightly unusual that a temporary sign would be multilingual when most permanent signs are in English, but the festival is a cultural and religious celebration so it makes sense to emphasise these aspects through use of Tamil.
Note: When a word is part of multiple languages, I assume the intention was to write in Tamil, given the encouragement of Tamil on the website. However there are some shared words and mutual intelligibility between Indian languages so some words may be inclusive of several Indian languages. For instance, “prasatham/prasadam”, mentioned in the 2nd image, is consistent across Malayalam, Telugu, Tamil and Sanskrit (and is “prasada” in Kannada.)