inside

Are these sentences correct:
[color=red]1-When he put on the suit we asked him to try and move about inside.
[color=blue]2-When he put on the suit we asked him to try and move about inside it.
[color=indigo]3-When he put on the suit on we asked him to try and move about in it.

Meaning: When he put on the suit we asked him to try and move about with the suit on.

Only sentence 3 has your intended meaning. The other two indicate that he should try moving his body inside the suit.