Hey Numan,
Thanks for reaching out!
It is not compulsory to add the word "late" before your father's name in your 10th,12th or diploma certificate even if he passed away long ago. Educational boards and most official documents, only require the name as per in birth certificates and other original records,and there's no legal or formal requirement to add "late" before his name in your educational records.
Infact,adding it unnecessaryily can create some issues if it doesn't match with the records in official documents. So,Its always safer to maintain consistency by using your father's name exactly as it appears in your earlier documents, without adding "late" unless specifically instructed.
Hope this clears your doubt!
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