k. An unlimited amount of 1/8”, braided, nylon rope
b. Any parts which are identical to legal VEX parts. For the purposes of this rule, products which
are identical in all ways except for color are permissible.
Just to verify K is independent of B and I am allowed to use longer than 12 inch long string?
If the string has to be limited to 12 inches can I buy longer segments and cut them to 12 inches long?
Yes, k. is independent of b. You may use any length of 1/8" braided, nylon rope.
Thanks Karthik 
Does that amount of string in the braid matter?
What about rope braided from the rope legal from R7K? Can I buy this from another supplier or should I braid them together myself?
Were all the company did was braid them together.
No, it does not matter. As long as the overall diameter is 1/8" the amount does not matter.
You may braid legal pieces of rope together. However, you may need to demonstrate to inspectors that this is indeed legal pieces of rope that have been braided together, as opposed to a single piece of rope with a diameter greater than 1/8".
Thanks for the really fast reply Karthik.
You’re welcome!