Only download ROMs for games you physically own. If you have the original PlayStation disc, you can rip it to a .bin / .cue or .chd file using a USB CD/DVD drive and software like dd or Imgburn on Windows. Alternatively, if you purchased Tekken 3 on PSN, you may legally obtain a backup.
Before diving into solutions, it helps to understand the problem. In the late 90s, Apple’s gaming market share was minuscule. Namco focused on Sony’s PlayStation and the arcade (System 12 hardware). Porting to Mac OS Classic would have required costly reverse-engineering and offered little return. tekken 3 for mac
Open the downloaded .dmg file and drag the application into your folder. Only download ROMs for games you physically own