Assuming you have a good understanding of Fiber print settings in C6, you can proceed to slice a part with fibers by enabling Print Fiber option in Advanced Settings.
Start with default settings for fiber.
C6 Fiber Print settings
Use a Fiber compatible part
A fiber compatible part is where required portions can be printed with Fiber, without a length based restriction (as explained in Fiber 3D Printing nuances)
E.g. If you're planning to print fiber walls, a part where each of the perimeter has a length more than the Fiber Cut Distance will work nicely. Also, because of minimum turn radius for fiber, it is recommended to avoid sharp corners.
A brake lever can be a compatible part for Fiber print
Post processing
A quick glance on the g-code preview tells us that the fiber slicing was successful, and we can see fiber walls on the outer perimeter of the part. Since we chose only 1 fiber wall, total 3 walls are printed (1 outer plastic wall + 1 fiber wall + 1 inner plastic wall)
Fiber laid after the cut action is visible in lighter gray.
A brake lever part sliced with fiber walls using C6
You can observe that inner holes in the brake lever did not get a fiber wall. This is because the Fiber Cut Offset was given as 90mm. This distance is more than the single perimeter of the inner holes. Hence no fiber in the inner holes. (More details in Fiber 3D Printing nuances)
(Fiber laid after the cut command is visible in lighter gray. This gives you a clear idea of how long is the Fiber Cut Offset. )
Walls without fiber
Those walls which couldn't accommodate fiber due to perimeter length, an equal count of walls is printed with plastic walls.
Non-fiber walls are printed with plastic with equal count
Fiber Legend and Info
You can also see there are extra legend options when Fiber Slicing is used. The darker color is for Fiber Walls, the lighter gray is for the fiber that is laid after cut.
Nozzle 2 material length gives info about how much fiber will be required for this print.