In the objective of a mission I need to capture the eclipse, can anyone tell me how to do that? I attacked the eclipse and it won't destroy even it's health is 0, and I tried to move the tyber zann's ship to it but nothing happens

Start by attacking the stations nearby, aiding the rebel fleets. Wait until at least one or two stations are destroyed, then send the shuttle. I sent it above it, so even though it took longer, the enemy were too distracted with the other ships to focus on the shuttle. Once the shuttle gets near, it should start the capturing sequence.
Oh, and whatever you do, you'll want the eclipse to have as much health as possible, so don't attack it.

You have a shuttle displayed with an arrow marker pointing to it. Send it to the Eclipse and once it's in range, it automaticaly begins bordering and you'll shortly have it under your control. I recommend taking out the first two stations atleast, and then leaving the Rebels to handle the third so you can pick them off suddenly.

And a side note: if you have trouble ending the mission (destroying all remaining imperials), a TIE squadron is usually stuck in the top left hand corner. I had to restart the thing three times before I realised, so just a notification.