Hi, I am building my first rc plane. I am using two servo for aileron. Do I need to connect Y-cable for that?   

if u have a 6 channel tx rx then its not required ...but if u have only 4 channels then u need a y cable

  I have 9ch tx and rx. To which Chanels do i need to plug the two servos.

Channel 1- 1st aileron
Channel 2- elevator
Channel 3- throttle
Channel 4- rudder
Channel 5- leave it
Channel 6- 2nd aileron
This configuration is for fly sky radio which i have
Enjoy

2 set up 2 ailerons, i just configure a flaperon setup on my tx... i also have the fsth9x.... connect one servo to ch1 and one servo to ch6.... then go to menu>settings>flaperon. change state to act, and configure as per your needs... it helps as an extra feature for ailerons....

yea aniket i also do that....but can u tell me for making it work like flaps as well as aileron...pm me need help for that..

yash, here are settings for my flaperons...
menu>Func settings>Flaperon

STATE ACT
AiL1 100 100
AiL2 100 100
FLP1 100
FLP2 -100

Anikethan : if you are beginner and your building first rc plane then i suggest you to build simple dihedral wings or polyhedral because these wings doesn't required ailerons and it glides well.

can help me i  m confuse  how work ch1 and ch 6 ?