You only have 2 tax returns-
IT-203- NY Nonresident and Part Year Resident return
NJ-1040 (resident return- allocated as a Part Year Resident)
NJ is one of few states that require taxpayers to file 2 separate tax returns as part year and nonresident. The IT-203 for NY covers both the income you made there as well as the income you earned there while a resident. You do not file 2 NY tax returns for the nonresident and resident periods.
You do need to allocate the portion of the NY income/ tax paid to NY while a resident of NY on the NJ part year return.
