Hi Kunwar,
Your situation is certainly concerning. I would suggest you to be practical and take the right decision and would urge you to think over the following.
1. Your application for Canada PR is under process, you haven't received your medical request so far and you are not sure whether you will be receiving soon. - At this stage, I would suggest you to obtain your CAIPS notes to see the status of your Canada PR - May be you can take some good decision. The process might well still take a year or more.
2. On the other hand, if you don't take a decision, you will have to leave Australia when your student visa expires or you may have to obtain another student visa to be able to stay back in Australia. Your visa office is Sydney, hence it is advisable that you remain in Australia until you have received your Canada Immigrant Visa else you may have difficulties in sending the passport for stamping and a hell lot of tensions are involved.
3. If you are 100% sure that you will be getting your 457 Visa which eventually will lead to Australia PR, it is not a bad bargain, as in my opinion, Australia and Canada are at par with each other - Both are lovely. Moreover, you have earned your education in Australia, which would certainly be more valuable in Australia than in Canada. So, getting your Australia PR should not be a bad thought as well.
4. You can apply for TR - 485, if you are meeting the requirements and even if you are not meeting the requirements, you can still apply and be on bridging visa until the decision has come and nowadays it takes around a year to get the decision on your TR visas. Hence, with little money you would be able to stay back in Australia....
Lastly, you are the best judge of your present / financial situation...
May god help you take the best decision
