Indicate by check mark if the registrant is submitting
the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(7):

Yes ______ No ___X___

Indicate by check mark whether by furnishing the information contained in this Form,
the Registrant is also thereby furnishing the information to the Commission pursuant
to Rule 12g3-2(b) under the Securities Exchange Act of 1934:

Yes ______ No ___X___

If “Yes” is marked, indicate below the file number assigned
to the registrant in connection with Rule 12g3-2(b): N/A

GAFISA S.A.

CNPJ/MF n° 01.545.826/0001-07

NIRE 35.300.147.952

Publicly-held Company

NOTICE TO THE MARKET

São Paulo, SP, Brazil, November 21, 2017 - GAFISA S.A. (BOVESPA: GFSA3) (“Gafisa” or “Company”), makes available to the market the following notice received on this date:

“The Grupo GWI, through its administrator GWI Asset Management S.A., headquartered in the City and State of São Paulo at Av. Brigadeiro Faria Lima, nº 3900, 6º andar, pursuant to CVM Instruction No. 358/2002, amended by CVM Instruction No. 449/07, hereby informs that at trading sessions of BM&FBOVESPA over the last days, ACQUIRED common shares issued by Gafisa S.A. enrolled with the corporate taxpayer’s ID (CNPJ/MF) No. 01.545.826/0001-07 (“Company”), and now holds the total amount of two million, eight hundred, twenty-six thousand and two hundred ninety-six (2.826.296) common shares, corresponding to 10.08% of the Company’s shares.

The Fund points out that this share acquisition has the sole purpose of investment, also informs that (i) it neither holds warrants, share subscription rights nor debentures convertible into shares issued by the Company; and (ii) it has not executed any agreement or contract regulating the exercise of voting right or the purchase and sale of securities issued by the Company.

There being no further matter to discuss, we remain at your disposal for any clarification.”

São Paulo, November 21, 2017.

GAFISA S.A.

Carlos Calheiros

Chief Financial and Investor Relations Officer