Usually it's between 2-6 months, unless you get selected for extra screening which might take up to a year and sometimes even longer (but this is rarely the case, most background checks are done within 2-6 months). One thing I also noticed recently that even if your application is ready to be finalized they won't finalize it early. Lets say for example this month the officers responsible for making final decisions are making decisions for the June/July 2017 applications and you're a Feb 2018 applicant and your file is ready to be finalized, they won't finalize it with the June /July 2017 applicants and instead they'll make you wait in queue until it's your turn (which is only fair). I noticed this since I'm an October 2017 applicant and my file has been queued for decision for more than 2 months now. Good luck!