@Sai Kiran, As there is no provision for the revision of ECR, the employer can request the EPFO to cancel the ECR and refund the amount, then resubmit the corrected ECR and pay. However, penalties and interest would be applicable as per the new payment date.
If the employee is currently working (in which the payment was made wrongly), then it would be wise to adjust the difference amount in the present month. If the employee in question has left, it would result in a net loss for the employer, as the interest and penalty amounts may exceed the contribution amount.
Alternate Option
An alternate option is to fill out Form 3A and 6A in the old format for all employees in the respective periods and submit them to the EPFO with remarks to adjust the same in the correct UAN. However, this would require human efforts and regular follow-ups with the department. The department may request further clarifications from the employer during the scrutiny of submissions.