Dear Sneha,
Please refer Paragraph 33 & 61 (1) under the The Employee Provident Fund scheme, 1952 and Paragraph 18 of the Employees Pension Scheme, 1995 wherein it is mentioned to submit the Declaration / Nomination form no 2 to conferring the right to receive the withdrawal / pension benefit in the event of his death, which itself stating that the submission of form is mandatory.
Secondly these details will help to update Form 9, which is a bible for PF dept to follow and proceed your claim.
Regards,
Janardan