Sorry to hear about your loss. Yes, the nominees of the deceased employee are eligible for the EDLI Benefit. You need to process the claim through the "Composite Claim Form in Death Cases" ([Form-20 (PF Payment)/Form-10-D (Pension)/Form-5 IF (EDLI)]). All claims can be applied for using this single form.
You need to collect the Death Certificate, proof of Marriage (in case of a married employee), Legal Heir Certificate, Bank Account details, etc., from the nominee of the employee.
By the way, how long did the deceased employee work with your organization?