If you are a registered voter at your correct poll site and are told you cannot vote, please be advised that you are entitled to an affidavit ballot.  Ask for one.

Here is what the NYC Board of Elections states: 
“If you are not on the poll-list, ask the inspector to verify that you are at the proper table for your address. Make sure that it is your correct Election and Assembly District. It may be because your registration form was not received by the deadline or, for a primary, because you aren’t enrolled in a party. If you believe that you are eligible, you can still vote. Ask for an affidavit ballot. After the election, the Board of Elections in the City of New York will check its records and your vote will be counted if you are indeed eligible to vote and are at the correct poll site. If not, you will receive a notice that you are not eligible, along with a registration application for future elections.”  For more information, visit the New York State Board of Elections, New York City Board of Elections, or Check Your Registration Status her. Also, you can call 866-VOTE-NYC, 866-868-3692 or TTY 212-487-5496.  Outside NYC call 212-VOTE-NYC.