If you own a co-op, there will be no deed, as what you own is shares of stock in the corporation that owns the building. There would be a stock certificate, which you would have received with your closing materials. In the alternative, it may be with your bank. If you've bought a condo, the deed would be accessible online through the ACRIS website, which is the Automated City Register Information System. You can access it at:
Halstead Property, LLC
http://a836-acris.nyc.gov/Scripts/CoverPage.dll/lookup click on this link and look up your block & lot number by entering the address and then search for documents.
If you need help, I'd be happy to offer further guidance.
Charlie Summers, Bellmarc 917-376-1648 or email@example.com