@narenjasti9 , assuming that your entry on F-1 in 2015 was your first entry ,allowing for 5 calendar years of being exempt individual and that you are/were not married to a US citizen/Resident ( joint filer ), you would have started counting days present for SPT ( Substantial Presence Test ) from Jan 1st. 2020. Thus you would have become a Resident for Tax purposes for 2020 and therefore file your return on form 1040 and NOT 1040-NR
Does that close your query?
Namaste
pk
