* Coil - This is a common and practical term for a collection of ropes, especially when they are wound together.
* Bundle - This term suggests a collection of ropes tied or wrapped together.
* Fathom - While this term refers to a unit of measurement for rope length, it could also be used figuratively to describe a large collection of ropes.
* Skein - This term is more commonly used for yarn, but it could be applied to a collection of thin ropes.
Ultimately, the best collective noun to use will depend on the specific context and the type of rope being described.