16MJ-16MJ-16FP TEE

That's exactly what this fitting handles. Both run ports are Male JIC SAE 37-degree flare at 1-5/16-12, so they'll mate with standard JIC female fittings on your line. The branch port is a 1-11½ Female NPTF, which gives you a pipe thread connection right there at the junction. Forged steel construction and a 3,000 PSI dynamic pressure rating make it a solid choice for working hydraulic systems where JIC and pipe thread meet at the same point.

Forged from steel, this tee fitting is rated to a maximum dynamic pressure of 3,000 PSI, so it should work fine.

For the run, both straight-through ports are Male JIC SAE 37 degree flare in 1-5/16-12 (SAE J514). The branch is a 1-11-1/2 Female NPTF port (SAE J476), so it is meant for exactly that kind of mixed setup where JIC is on the run and pipe thread is on the branch.