what does six months visa really ( M )

Hi my problem is that I have six months M and it expires in September but what I came to china to do am not even half way through i have been here close to 2 months now, I have gone through the residence permit and I have the temporal residence permit. I want to see my goods produce for me in the right quality and quantity the last time I place order my suppliers gave me default goods so I have come here personallly to get my goods but am afraid am overstaying I need advice please