I (Indian citizen) with my wife visited to Perth ( Australia) on visitor visa. We along with my sister (Australian citizen) wants to visit Canada on Visitor visa.
Is it possible to get?
There are no problems. You can apply for the visa online and only visit VFS Global in Australia to give biometrics, hand over passport etc. See for example the Where to give your fingerprints and photo (biometrics) page
You can go to one of these official locations to give your biometrics:
visa application centres (VACs) worldwide
Nowhere does it say "a VAC in the country where you are resident" or similar.
In very vague terms this is true worldwide. If you review our "Related" sidebar you will see similar questions for different countries eg I am an Indian citizen touring Australia on a visit visa. Can I apply for NZ visa from Australia? and Can I apply for US visa while I am a visitor in Canada?