UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K Report of Foreign Issuer Pursuant To Rule 13a-16 Or 15d-16 of the Securities Exchange Act of 1934 For the month of April 2023 Commission File Number: 333-251238 COSAN S.A. (Exact name of registrant as specified in its charter) N/A (Translation of registrant’s name into English) Av. Brigadeiro Faria Lima, 4100, – 16th floor São Paulo, SP 04538-132 Brazil (Address of principal executive offic es) Indicate by check mark whether th ...