Super Scope 6 refers to a package of six games along with the Super Scope light gun device. The Super Scope was the Super Nintendo version of a light gun but it was designed to look and be held more like a bazooka. Back when the original Nintendo came out, it was packaged with a light gun and a light gun game (Duck Hunt) but they never really caught on as a mainstream genre. From time to time a major light-gun game would come out but they have always been few and far between.
The Super Scope 6 package included six games but this is really a little misleading. They are more like mini-games and it's more like two games, each with three variations. They were all on one cartridge. These games included Blastris (Blastris A, Blastris B, and Mole Patrol) and LazerBlazer (Type A: Intercept, Type B: Engange, Type C: Confront).
There were also a few major standalone games release for the Super Scope including Operation Thunderbolt, Battle Clash, Bazooka Blitzkrieg, Metal Combat: Falcon's Revenge (sequel to Battle Clash), T2: The Arcade Game, Tin Star, X-Zone, and Yoshi's Safari. A few others used it as more of a gimick as an alternate way to play or for a minigame stage. These include The Hunt for Red October, Lamborghini American Challenge, and Lemmings 2: The Tribes.
Not to be outdone, Sega released a similar peripheral called the Menacer for the Sega Genesis. It had even less support that the Super Scope.
Light gun games have continued to be a feature of modern gaming systems though the technology has changed. The technology used in the Super Scope and in light guns that would follow for the PlayStation, PS2 and Saturn relied on the use of a CRT based television. A different technology was used in light guns for the PS3 that allowed them to work with flat screen TVs. Starting with the Wii, most systems have gone to motion sensing technology for this purpose.
For emulation purposes, emulators generally emulate these older CRT based light-gun technologies using the mouse. There are third party guns you can buy that work by simulating a mouse though I'm not sure how well these work with the various emulators.