First thing Vignesh, is that you should not have been appointed to this job.
Most states under the factories rules have specified qualification of the safety officer and generally need training in the same before they are appointed. I would suggest you check your state rules and immediately arrange to get the relevant training and certification in place.
For the immediate problem, you need to file an accident report with the Factory Inspector (within 24 hours of the accident) and with the ESIC office if the person concerned comes under ESIC. If the employee is not covered under the ESIC act, then compensation under Employees Compensation Act must be computed and deposited with the relevant authority.
Also if you have any insurance cover under which this accident falls, you must immediately report the same to the insurance company.
Then you need to investigate the matter to find out how and why the accident took place, whether requisite safety equipment was provided and used, whether anyone was responsible or anyone whose carelessness resulted in the fatal accident. Further, you need to identify the changes needed to prevent the accident from recurring.
In most companies, the report as above needs to be immediately placed before the safety committee and decisions / action taken immediately.