The remedy available is to convince the Manager, Local Office and the person concerned in the Sub Regional Office of the ESIC that due to oversight you missed to upload the accident report and then upload it now if possible. When you upload a report of accident which happened some days back (I believe even three days back) in the online portal, a pop up will appear to show reasons for non submission of the accident report in time and you can submit your reply there itself. You can try this. Since it is an accident outside the plant, in a road, you have to prepare a sketch of the road where the accident occurred and attach the FIR, if available. These can be submitted offline separately with a covering letter explaining the delay.
If the employee does not get the benefits from the ESIC due to your negligence, then you, the employer, will have to meet the expenses, pay the salary for the period of absence and compensate the loss incurred following the provisions of the Employees Compensation Act.
From India, Kannur