For someone with a job offer from a Canadian employer (not started though yet), what are the options for PR application ?
Can they apply for PR via express entry with 50 points for job offer, even before starting the job in Canada and even before travelling to Canada ? (Assuming they meet the cut off for CRS).
Or do they have to wait for completion of 1 year in job before even attempting to apply for PR via express entry or other avenues?
Yes you can apply and get those points and wait for EE to process. However you may want to start work soon (typically no employer waits for 6 months for you to join). Try to get a work permit. It’s ok if you have EE processing side by side.
If your EE goes through you get the PR. If not or you decide not to get EE, you can try CEC after one year of working there.