If you are selling in NYC, you will have lots of taxes (and closing costs to pay). Here are some of the biggest ones:
1. Commission - 6% (you can pay less if you sell FSBO)
2. NYC/NYS Transfer Taxes - 1.425% - 1.825%
3. Flip Tax from co-op, do you know if your building has one?
After closing costs, you will likely have to pay capital gains tax. You need to speak with an accountant on this matter, but this provides a pretty good general overview on capital gains taxes for NYC real estate: https://www.hauseit.com/nyc-real-estate-taxes/