Which musical instrument is associated with the grand staff and ranges from F1 to F6?

The grand staff is a notation system that combines the treble and bass clefs, which is most commonly associated with the piano. The piano ranges from A0 to C8, which encompasses a wide range across multiple octaves, including from F1 to F6. This broad range makes the piano highly versatile for playing various music styles and compositions.

The harpsichord, while also capable of producing music in a similar notation context, typically has a more limited range than what is associated with the grand staff in a modern context. The harmonium and organ also utilize the grand staff, but their ranges differ significantly from the specified F1 to F6, with the piano being the most typical instrument that musicians reference when discussing this range alongside the grand staff.

Choosing the piano aligns with both the grand staff notation and the specific pitch range mentioned in the question, making it the correct answer.