Hi. You dont need an "Y" if you use P.Mix function on your radio... Put one elevator servo on channel 2, and other on (5 or 6). Assuming you have dual servos on ailerons, you'll need to put it on channel 5. Then choose p.mix funtion with channel 2 as master, and channel 5 as slave. Make the adjustments and it should work.

I used it already on my T6XAs, yours should be the same..