Step 1: Know the rule.
Order XXIII of the CPC, 1908 deals with withdrawal and abandonment of suits. It balances the plaintiff's freedom with the need to stop repeated suits.
Step 2: Check Statement I.
A plaintiff may withdraw or abandon a suit subject to the law. This is allowed under Order XXIII Rule 1. Statement I is correct.
Step 3: Check Statement II.
To file a fresh suit on the same cause of action after withdrawal, the plaintiff needs the court's permission. Statement II is correct.
Step 4: Check Statement III.
If the plaintiff withdraws without getting permission to sue again, a fresh suit on the same cause is barred. Statement III is correct.
Step 5: Check Statement IV.
The court does not have to grant permission whenever asked. It grants it only for a formal defect or sufficient grounds. So permission is discretionary, and Statement IV is incorrect.
Step 6: Final answer.
Statements I, II and III are correct.
\[ \boxed{\text{I, II and III}} \]