They're heading for the medical frigate.
1 seconds sound clip from the Star Wars: Episode VI - Return of the Jedi movie soundboard.
You can hear this line at 01:40:48.276 in the Blu-ray version of the movie.
Quote context
[...]
- Going? What do you mean, you're going? Going where, R2?
- No, wait! This is no time for heroics! Come back!
- Watch yourself, Wedge. Three from above.
- Got it.
- Three of them coming in, 20 degrees. Cut to the left. I'll take the leader.
- They're heading for the medical frigate.
- Only the fighters are attacking. I wonder what those Star Destroyers are waiting for.
- We're in attack position, sir.
- I have my orders from the Emperor himself. He has something special planned for them.
- We only need to keep them from escaping.
[...]