I DO NOT DO NY TAX RETURNS, but

Try Screen 51 > New York Subtractions S-122 Certain railroad retirement income

Certain railroad retirement income

Enter the amount of certain railroad retirement income and railroad unemployment insurance benefits.

This amount is included as a subtraction on Form IT-225, Schedule B, Part 1.

------------------------  From the instructions for IT-225 ------------------

S-122 Certain railroad retirement income and railroad
unemployment insurance benefits
Enter supplemental annuity or Tier 2 benefits received under
the Railroad Retirement Act of 1974, or benefits received under
the Railroad Unemployment Insurance Act that are exempt from
state income taxes under federal laws (but that you included in
your federal income).