about suitable encoder for DUAL SHAFT MOTOR - D5065 270KV?

could you please explain which encoder is suitable for DUAL SHAFT MOTOR - D5065 270KV

This is going to depend more on your application, which ODrive device are you using? If you have a Pro or S1 I would suggest the AMT21, alternatively if you have any v3 ODrive you could use the amt10E. We also have an encoder spreadsheet that compares a lot of common/tested encoders.

Hope this helps!