I have a six hour overlay in Shanhai, is there quick sightseeing tours?

I think it hard for you to join a sightseeing tour in such a short time. If you want to see, you can travel by yourself. You can take Maglev and then subway line 2 to reach Lujiazui Station to see the Oriental Pearl in Pudong area and then take the same line to reach West Nanjing Road and Jing'an Temple. In the end take the same line to go back to the airport.