Incorrectly filed return for deceased father

IB Agrawal (Director) (20 Points)

10 August 2021  

Hello this is my first post. My father passed away on 20/06/2020. He was a pensioner and was efiling income tax return every year. After his death, I registered as legal heir on the IT portal and efiled his return for FY 2019-20 as his representative assessed (legal heir). I think that was a mistake because it appears I should have filed the last return (for the period 01/04/2020 to 20/06/2020) as representative assess and not for FY 2019-20. Now, the IT portal does not offer me the option of filing as representative assessee.

My father has pension of about 4 lakh from 01/04/2020 to 20/06/2020. I cannot file on his behalf and I cannot club this income with my own because it is pre-death. What do I do? Will be grateful for any guidance.