Yes, but not both. You have ground to air, ground to ground, ship to ground, ship to ship. For the most part (with some standouts that do multi-role such as the Tomahawk) each munition is specialized for a single role. The railgun is being heralded as being capable of doing all 3 for limited use cases, which is fairly unique.
The SM-6 is anti-air and anti-ship. It has the option to add GPS guidance to it (SM-6 Block IA and the newer IIA), but it is much more expensive as a Tomahawk and is generally not used for this case. A Tomahawk is around $1.4 million per whereas the SM-6 Block I was $5.6 million per and the newer full rate production version (Block IA and newer) is $4.8 million per.
For reference, the Hypervelocity Projectile (made by BAE Systems) that Railgun fires comes down to a unit cost of $86,000-$90,000 per shot depending on what source you read. So ~$90,000 per railgun shot gives you ~53 shots from the railgun for every single SM-6 when it comes to cost. This is entirely game changing from an economics perspective with similar capabilities. By lacking rocket motors or being explosive, it is also much safer to transport so you can likely pack more ammunition onto a ship.
