Well, no.
There are quite a few differences between Cat6 and the other Catagory-rated structured cabling components (Cat{5e, 5, 4, 3}).
While there *are* some shielded Cat6 cables out there, many/most are not.
In fact, if the OP had a chunk of *shielded* Cat6, it would be a Very Bad Thing to mix shielded and unshielded cabling in a single run (without the benefit of a shielded cable-type panel that is properly grounded and terminated).
Ungrounded (or poorly grounded / terminated) shielded cabling performs somewhere in the neighborhood of rusty barbed wire sitting under a high tension power line. The (improperly terminated) shielding acts like an antenna and usually does a great job of sucking in noise to put on the conductors..
The termination specification for Cat6 is also much more stringent, compared to lower rated cabling with a "Category" certification. The conductors tend to be larger guage, the overall diameter tends to be larger because of the (usual) use of an X-member/insulator/pair separater.
There are a lot of differences between Cat6 and the other stuff but, as mentioned, simply using Cat6 jumpers in a system that also uses Cat{5e, 5} jumpers should work OK.
The overall system will assume the characteristics of the lowest-rated component.
FWIW
Scott