Mollies are beautiful fish...but they like clean water, some extra algae to nibble on, and do best with a little bit of salt in their water. The water will stay cleaner, and the fish healthier, if they are not overcrowded. I would therefore not recommend putting much else in with them (and they are plenty beautiful and interesting by themselves). Chinese algae eaters can get aggressive as they grow, and I would skip that. Likewise Corys like to be kept in groups, and do not like salt in their water, so I would skip them. Keep them by themselves and they will probably do best!

Guppys, Platy, Swordtails, Neons, Zebras,....

One big problem is mollies need a bigger tank than a 6 gallon. They need a tank of at least 30 gallons to do well. They like warm water and some salt added to the tank, sea salt of the type used in saltwater aquariums works best because mollies in nature are found near the coast and in saltwater.

Keeping a single cory is cruel, and keeping one in a brackish tank is even more so. Cory cats are schooling fish and need at least 6 of a single species to be confident and comfortable. They are also Amazon fish and need a totally different water chemistry than do mollies, that are, as already noted; brackish to salt water fish.

I also agree about the tank size. 6 gal. is barely enough to support just one or 2 of the fish you wrote you plan to keep, let alone 5 or 6 of them.

You could however, get away with a half dozen fish of a species that stays very small, such as one of the small rasboras.

It's really a shame that pet stores sell those tiny tanks, then don't stock the only fish suitable for them, such as some of the really small, "micro" species.

For instance: You could keep a school of a dozen Chilli Rasbora in a planted 6 gallon tank and they would be happy and- give their keeper a real treat. Tiny, brilliantly colored, and hardy.