UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

FORM 8-K

CURRENT REPORT

PURSUANT TO SECTION 13 OR 15(D)

OF THE SECURITIES EXCHANGE ACT OF 1934

Date of Report (Date of earliest event reported): May 12, 2025

Rigel Resource Acquisition Corp

(Exact Name of Registrant as Specified in Charter)

(646) 453-2672

(Registrant’s telephone number, including area code)

Not Applicable

(Former Name or Former Address, if Changed Since Last Report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions (see General Instruction A.2. below):

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

Securities registered pursuant to Section 12(b) of the Act:

Emerging growth company ☒

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

On November 1, 2024, CBIZ CPAs P.C. (“CBIZ CPAs”) acquired the attestation business of Marcum LLP (“Marcum”), and substantially all of the partners and staff that provided attestation services for Marcum joined CBIZ CPAs. Accordingly, on May 12, 2025, as a result of the acquisition, Marcum resigned as the independent registered public accounting firm of Rigel Resource Acquisition Corp (“we,” “our,” “us,” “Rigel” or the “company”) and, with the approval of the Audit Committee, CBIZ CPAs was engaged as our independent registered public accounting firm for the fiscal year ending December 31, 2025.

The audit reports of Marcum on our consolidated financial statements as of and for the fiscal years ended December 31, 2024 and December 31, 2023, respectively, did not contain an adverse opinion or a disclaimer of opinion, and was not qualified or modified as to uncertainty, audit scope, or accounting principles, except for a paragraph relating to substantial doubt about the Company’s ability to continue as a going concern.

During the fiscal years ended December 31, 2024 and December 31, 2023, and through May 12, 2025, there were (a) no “disagreements” (as defined in Item 304(a)(1)(iv) of Regulation S-K and the related instructions) with Marcum on any matter of accounting principles or practices, financial statement disclosure, or auditing scope or procedures, which disagreements, if not resolved to the satisfaction of Marcum, would have caused Marcum to make reference to such disagreement in its report and (b) no “reportable events” (as defined in Item 304(a)(1)(v) of Regulation S-K) other than the fact that our management concluded there existed material weakness in our internal controls over financial reporting for the fiscal years ended December 31, 2024 and December 31, 2023, as disclosed in Part II, Item 9A of the Company’s Annual Report on Form 10-K for the years ended December 31, 2024 and 2023.

During the fiscal years ended December 31, 2024 and December 31, 2023, and through May 12, 2025, neither we nor anyone on our behalf consulted with CBIZ CPAs regarding (i) the application of accounting principles to a specific completed or contemplated transaction or regarding the type of audit opinions that might be rendered by CBIZ CPAs on our financial statements, and CBIZ CPAs did not provide any written or oral advice that was an important factor considered by us in reaching a decision as to any such accounting, auditing, or financial reporting issue or (ii) any matter that was either the subject of a “disagreement” (as defined in Item 304(a)(1)(iv) of Regulation S-K and the related instructions) or a “reportable event” (as defined in Item 304(a)(1)(v) of Regulation S-K).

We provided Marcum with a copy of this Current Report prior to its filing with the Securities and Exchange Commission (the “SEC”) and requested that Marcum furnish us with a letter addressed to the SEC, pursuant to Item 304(a)(3) of Regulation S-K, stating whether it agrees with the above statements and, if it does not agree, the respects in which it does not agree. A copy of the letter, dated as of May 12, 2025, is filed as Exhibit 16.1 to this Current Report.

SIGNATURE

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