@yk6 first Namaste ji
second, based on your note it appears that by the end of the year 2019, you had met the substantial presence test and therefore for 2020 you would have been a Resident Alien for Tax Purposes and be taxed on your world income.
Third, because your actual work was done in India ( remotely ) the income for that period , even though by an US entity, is foreign income for US purposes. India would probably treat this income as in-country sourced and tax the income . It also means that your employer probably should not have collected State and FICA taxes .
Fourth, give the situation, you should get a corrected W-2 showing ONLY the US sourced income and the actual withholding. This would mean that (a) you file and finalize the Indian Return and then (b) prepare the US return wherein you recognize your world income ( US sourced and the Indian sourced ) and taxes paid to India ( on the India sourced income). This way you can indeed get foreign tax credit for the taxes imposed by India on the India sourced income. The ratio of foreign income to world income should allow you get essentially the full credit for foreign taxes ( depending on the tax rate imposed by India ). Also there would be no State tax on the foreign income ( because you were not in the state---- this depends on the State in question, though.
Is there more I can do for you ?
