I've easy star II with dual ailerons each having separate servos.
I know we can use Y connector and operate both on same channel. I've Turnigy 9X radio and I tried flaperons, channel mixing but I was not able to use both ailerons using one channel.

Anybody have suggestions.

Sunil,
with a Y connector, both servos would rotate in the same direction. So if the servo arm has two sides like, connect one wing on the Left hand of the servo arm, while the other on the right. This would ensure that both the control surface move in opposite direction
Pankaj

Or simply plug the two servos in two different channels on your receiver and electronically mix them on your radio. Flaps will not work when using a single channel to operate two servos on aileron.