TIMB 6-K

UNITED STATES
SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549

FORM 6-K

REPORT OF FOREIGN PRIVATE ISSUER
PURSUANT TO RULE 13a-16 OR 15d-16
UNDER THE SECURITIES EXCHANGE ACT OF 1934

Date of Report: January 27, 2026

Commission File Number: 001-39570

TIM S.A. (Exact name of Registrant as specified in its Charter)

João Cabral de Melo Neto Avenue, 850 – North Tower – 12^th^ floor
22775-057 Rio de Janeiro, RJ, Brazil (Address of principal executive office)

Indicate by check mark whether the registrant files or will file annual reports under cover of Form 20-F or Form 40-F.

Form 20-F ☒ Form 40-F ☐

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(1).

Yes ☐ No ☒

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 ☒

TIM S.A.

Publicly-held Company

Corporate Taxpayer’s ID (CNPJ / MF) 02.421.421/0001-11

Corporate Registry (NIRE) 33.300.324.631

NOTICE TO THE SHAREHOLDERS

ANNUAL SHAREHOLDERS’ MEETING

TIM S.A. ("TIM" or "Company") (B3: TIMS3; NYSE: TIMB), pursuant to CVM Resolution No. 81/22, informs to its shareholders and the market in general of the rectification on the date of its next Annual Shareholders’ Meeting will be held on March 31^st^, 2026, as updated in the Company's Corporate Events Calendar. Additional information on this Meeting will be disclosed in due course, when the call notice and other related documents are disclosed.

Rio de Janeiro, January 27^th^, 2026.

TIM S.A.

Vicente de Moraes Ferreira

Investor Relations Officer

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.