As there is no provision for revision of ECR. but the employer can request the EPFO to cancel the ECR and refund the amount, than resubmit the corrected ECR and pay, however penalty and interest would be applicable as per new payment date.
if the employee is working at present ( in which the payment is made wrongly) then it would be wise to adjust the difference amount in present month,
if the subjected employee has left, then it would be a net loss for employer, as the interest and penalty amount may get higher than the contribution amount
alternate option is to make form 3A and 6A in old format for all employees in respective periods and submit to EPFO with remarks to adjust the same in correct UAN, but it would take human efforts and regular follow ups with department.
Department may recall the employer for more clarifications during scurtiny of submissions.