Is there an ap to let me run HyperCard in 10.6.8?

You can try an emulator like sheepshaver or get an older Mac that can run classic natively or in classic environment.

http://en.wikipedia.org/wiki/SheepShaver

http://en.wikipedia.org/wiki/Mac_68K_emulator

http://en.wikipedia.org/wiki/Classic_Environment

http://hints.macworld.com/article.php?story=20060509180914879

The Classic game Risk II running in Sheepshaver on my Lion Mac Mini:

[click on images to enlarge]

Here is a post I recently assembled for another similar question:

With the newer Intel Macs, you have to run a Classic emulator such as SheepShaver, which requires you to extract the Mac ROMs from your older Classic Mac and then install Mac OS 9.

A related program is Chubby Bunny, which comes bundled with all of that included (google the term "Classic-On-Intel v 4.0.1 chubby bunny").

More information on SheepShaver:

http://www.emaculation.com/doku.php/sheepshaver_mac_os_x_setup

and

http://www.everymac.com/mac-answers/mac-os-9-classic-support-faq/run-macos-9-on- intel-macs.html

and more information about Chubby Bunny:

http://www.macwindows.com/OS9_on_Intel_Mac.html#092408b

and

http://hackthemac.blogspot.co.uk/2008/08/chubby-bunny-old-virtual-machine.html

If you don't need a newer version, and if you don't need color, try Mini vMac, which emulates a Mac Plus and up to OS 7.5.5.