Most common snails found in local waterways are found around the world. We have Ramshorn, 2 species of Lymnaea, mini ramshorns, Malaysian livebearers and a number of other introduced species in creeks and ponds around Perth in Western Australia. Most of these snails have been here for years and are found in most fresh water creeks, rivers and ponds around the country, usually around cities and suburban areas. I presume they are also found in fresh water creeks and streams in most parts of the world.
There might be local species too and many of these can also be kept in tanks. However, you should contact your department of fisheries and see if they have a list of aquatic snails you can collect. Aquatic snails are not commercial species and most countries don't care if you take some for an aquarium.