In most cases, yes - you can use DSLR lenses on a mirrorless camera body, but most of them are not interchangeable. That means you would be able to use DSLR lenses only with a specific adapter that you would use to mount them to your mirrorless camera. The market of these adapters has also developed over recent years, so nowadays, you can pair pretty much any lens you already own with a mirrorless body.