What do you mean by "liberty to file a fresh suit"

If the plaintiff desires to file a fresh suit with new facts or pleadings or a new cause of action or to continue with the same cause of action at a later date then in the withdrawal petition he can mention a line requesting the court to permit him to file a fresh suit on the same grounds or different cause of action at a later stage.

This will enable him to avoid the rejection of fresh suit on the grounds of res judicata.

The on-going suit is allowed to be withdrawn and fresh case (suit) is permitted by the Court to be instituted on the same / new facts and cause of action.