Person is in US. H1 got approved in consulate process in year 2015. But went for visa stamping in the year 2017. So H1 is counted from 2017 or 2015. Thank you.
The H1B 6 year time starts when you start the H1B job. Visa is just a travel doc.
If you were on OPT when in US and went for stamping and entered the US on H1B status, you time starts from the day you start the H1B job.