I know that on TRV you can stay 6 months, on this forum you can find (just use the search engine)
This has been covered a lot here but bears repeating:
-Someone who applies for a visa with a PR application in process has a higher chance of the visitor visa application being refused.
-I believe current practice is that visitor visas are issued with a period of validity for entry to Canada (ie. if valid to June 30, you can enter June 29). This is separate from the allowed period of stay. (It's possible that some visas may specify slightly different conditions, I don't know)
-Again, on arrival usually they seem to allow up to six months stay, but the decision is to some degree with the border officer. It's stamped in passport. (i.e. they can put shorter periods even if they do not always do so).
-Very important: whether on a visa or from a visa waiver country, the border officer does NOT have to let the person in - notably if the officer determines the person intends to overstay or otherwise violate terms of entry.
-So for people with PR applications pending: plan as a visit, not as the start of your residency. Visitors who show up with no return ticket and all of their household goods and worldly belongings may well get refused entry. (Conversely someone showing up with a return ticket on a friday, a weekend bag and can show they have meetings on the next tuesday morning are going to look more credible in terms of intending to depart Canada). There is no way for anyone to say in advance how the border officer will treat a specific case in advance, they use their judgment.
YMMV.