There are many laws that regulate alcohol possession and consumption, and being under the influence of alcohol in New York City.
Consumption of Alcohol on Streets (Open Container, generally) -- NYC Administrative Code §10-125 (this is a violation):
a) an “alcoholic beverage” contains more than .005 alcohol by volume
b) a “public place” is a place like a street, shopping area, or park that the public has access to.
c) you may not consume, or possess with intent to drink or consume, an open container of alcohol in a public place
d) possessing an open container creates a presumption that you intended to drink it (although you can disprove this presumption)
Part of “Regulated Uses” of Parks - Parks Department Regulations §1-05 (this can be a misdemeanor or violation):
Behavior that is not allowed:
f) 1) drinking alcohol in park or possession (even closed) with intention to drink it
f) 2) appearing in park under influence of alcohol to degree that you endanger or unreasonably annoy others
Part of “Disorderly Conduct” in transit facilities -- Transit Authority Rule 1050.7 (this is a violation):
Behavior that is not allowed:
g) drinking alcohol or possessing an alcoholic beverage
h) entering or being in a station or train where your ability to function safely there is impaired by alcohol or drugs