Not sure what the 6 & 6 your are refering to, what type of motors, encoders and drives are you using?
If you are using a Galil card, the standard incremental differential encoders inputs allow for 8 encoder wires, +v, Common, A, /A, B, /B, I, /I.
The servo motor goes back to the drive, and the connections between drive and Galil depend on what make and features they have.
Unless your motors are DC brushless and then the encoder may have commutation tracks on it the go to the drive.
Al.
CNC, Mechatronics Integration and Custom Machine Design
“Logic will get you from A to B. Imagination will take you everywhere.”
Albert E.