If you own the software, you can grant specific people and institutions a GPL license for your software, and grant other people and institutions a commercial li

If you own the software, you can grant specific people and institutions a GPL license for your software, and grant other people and institutions a commercial license (and refuse to grant them a GPL license for your software). However, everyone who has received your software under the GPL can sublicense it to the people who you denied the GPL to. You can't forbid it, but they don't have to, and you can nicely ask them to never sublicense it.