If you live in NYC but work in CT, you will need to file both a CT nonresident state income tax return (to report only your CT sourced income) and an NY/NYC resident state income tax return to report all income (including CT sourced).
You
will want to work on your nonresident CT state income tax return first (if you did your NY first, you will want to delete it and start over with the CT nonresident return). You
will then take a tax credit from your nonresident CT state income taxes on your
resident NY state income tax return. (Please note that you will only get a tax
credit for your CT state income taxes up to the amount of NY state income taxes
that would have been paid if the income was earned in NY). The credit for
taxes paid to another state section will be at the end of your residence
state's interview process.
Just
follow the TurboTax guide when working on your states (remembering to do your
nonresident state return first) and TurboTax will do all the calculations and
credits to your resident states return.
Here
is additional information about filing in multiple states (select "see
more answer" to view the entire attachment)
https://ttlc.intuit.com/replies/3300797