SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13G

UNDER THE SECURITIES EXCHANGE ACT OF 1934

M3-Brigade Acquisition VI Corp.

(Name of Issuer)

Class A Ordinary Shares, par value $0.0001

(Title of Class of Securities)

G63221108

(CUSIP Number)

09/30/2025

(Date of Event Which Requires Filing of this Statement)

Check the appropriate box to designate the rule pursuant to which this Schedule is filed:

Rule 13d-1(b)

Rule 13d-1(c)

Rule 13d-1(d)

SCHEDULE 13G

CUSIP No.

G63221108

Names of Reporting Persons

M3-Brigade Sponsor VI LLC

Check the appropriate box if a member of a Group (see instructions)

(a)

(b)

Sec Use Only

Citizenship or Place of Organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 8,625,000.00
6	Shared Voting Power 0.00
7	Sole Dispositive Power 8,625,000.00
8	Shared Dispositive Power 0.00

Aggregate Amount Beneficially Owned by Each Reporting Person

8,625,000.00

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

Checkbox not checked

Percent of class represented by amount in row (9)

20.0 %

Type of Reporting Person (See Instructions)

SCHEDULE 13G

CUSIP No.

G63221108

Names of Reporting Persons

M3-Brigade Acquisition Partners VI Corp.

Check the appropriate box if a member of a Group (see instructions)

(a)

(b)

Sec Use Only

Citizenship or Place of Organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 8,625,000.00
6	Shared Voting Power 0.00
7	Sole Dispositive Power 8,625,000.00
8	Shared Dispositive Power 0.00

Aggregate Amount Beneficially Owned by Each Reporting Person

8,625,000.00

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

Checkbox not checked

Percent of class represented by amount in row (9)

20.0 %

Type of Reporting Person (See Instructions)

SCHEDULE 13G

CUSIP No.

G63221108

Names of Reporting Persons

Mohsin Y. Meghji

Check the appropriate box if a member of a Group (see instructions)

(a)

(b)

Sec Use Only

Citizenship or Place of Organization

UNITED STATES

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 8,625,000.00
6	Shared Voting Power 0.00
7	Sole Dispositive Power 8,625,000.00
8	Shared Dispositive Power 0.00

Aggregate Amount Beneficially Owned by Each Reporting Person

8,625,000.00

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

Checkbox not checked

Percent of class represented by amount in row (9)

20.0 %

Type of Reporting Person (See Instructions)

SCHEDULE 13G

Item 1.

(a)

Name of issuer:

M3-Brigade Acquisition VI Corp.

(b)

Address of issuer's principal executive offices:

1700 Broadway, 19th Floor, New York, NY 10019

Item 2.

(a)

Name of person filing:

This statement is being filed on behalf of each of the following persons (each, a "Reporting Person" and, collectively, the "Reporting Persons"): 1. M3-Brigade Sponsor VI LLC 2. M3-Brigade Acquisition Partners VI Corp. 3. Mohsin Y. Meghji

(b)

Address or principal business office or, if none, residence:

1700 Broadway, 19th Floor New York, NY 10019

(c)

Citizenship:

See row 4 of the cover page of each Reporting Person.

(d)

Title of class of securities:

Class A Ordinary Shares, par value $0.0001

(e)

CUSIP No.:

G63221108

Item 3.

If this statement is filed pursuant to §§ 240.13d-1(b) or 240.13d-2(b) or (c), check whether the person filing is a:

(a)

Broker or dealer registered under section 15 of the Act (15 U.S.C. 78o);

(b)

Bank as defined in section 3(a)(6) of the Act (15 U.S.C. 78c);

(c)

Insurance company as defined in section 3(a)(19) of the Act (15 U.S.C. 78c);

(d)

Investment company registered under section 8 of the Investment Company Act of 1940 (15 U.S.C. 80a-8);

(e)

An investment adviser in accordance with § 240.13d-1(b)(1)(ii)(E);

(f)

An employee benefit plan or endowment fund in accordance with § 240.13d-1(b)(1)(ii)(F);

(g)

A parent holding company or control person in accordance with § 240.13d-1(b)(1)(ii)(G);

(h)

A savings associations as defined in Section 3(b) of the Federal Deposit Insurance Act (12 U.S.C. 1813);

(i)

A church plan that is excluded from the definition of an investment company under section 3(c)(14) of the Investment Company Act of 1940 (15 U.S.C. 80a-3);

(j)

A non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J). If filing as a non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J),
please specify the type of institution:

(k)

Group, in accordance with Rule 240.13d-1(b)(1)(ii)(K).

Item 4.

Ownership

(a)

Amount beneficially owned:

M3-Brigade Sponsor VI LLC (the "Sponsor") directly owns 8,625,000 Class B ordinary shares, par value $0.0001 per share ("Class B Ordinary Shares"), of M3-Brigade Acquisition VI Corp. (the "Issuer"), which are convertible into the Issuer's Class A ordinary shares, par value $0.0001 per share ("Class A Ordinary Shares"). Such shares may be deemed to be beneficially owned by M3-Brigade Acquisition Partners VI Corp. ("MBAP"), which is the general partner of the Sponsor, and Mohsin Y. Meghji, who is the sole director of MBAP. As a result of these relationships, each of the Sponsor, MBAP and Mr. Meghji may be deemed to have or share beneficial ownership of the securities held directly by the Sponsor. Each of the Sponsor, MBAP and Mr. Meghji disclaims beneficial ownership of such securities except to the extent of their direct ownership. In addition to the securities reported on the cover pages hereto, the Sponsor also directly owns 4,333,333 private placement warrants to purchase 4,333,333 Class A Ordinary Shares. The warrants become exercisable beginning 30 days after the completion of the Issuer's initial business combination and expire five years after the completion of the Issuer's initial business combination or earlier upon redemption or liquidation. Percentage ownership is based on 34,500,000 Class A Ordinary Shares outstanding as of October 8, 2025, as reported by the Issuer in its quarterly report on Form 10-Q for the period ended June 30, 2025, and 8,625,000 Class B Ordinary Shares directly owned by the Sponsor, and assumes conversion of such Class B Ordinary Shares into Class A Ordinary Shares. See row 9 of the cover page of each Reporting Person.

(b)

Percent of class:

See row 11 of the cover page of each Reporting Person.

(c)

Number of shares as to which the person has:

(i) Sole power to vote or to direct the vote:

See row 5 of the cover page of each Reporting Person.

(ii) Shared power to vote or to direct the vote:

See row 6 of the cover page of each Reporting Person.

(iii) Sole power to dispose or to direct the disposition of:

See row 7 of the cover page of each Reporting Person.

(iv) Shared power to dispose or to direct the disposition of:

See row 8 of the cover page of each Reporting Person.

Item 5.

Ownership of 5 Percent or Less of a Class.

Item 6.

Ownership of more than 5 Percent on Behalf of Another Person.

Not Applicable

Item 7.

Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on by the Parent Holding Company or Control Person.

Not Applicable

Item 8.

Identification and Classification of Members of the Group.

Not Applicable

Item 9.

Notice of Dissolution of Group.

Not Applicable

Item 10.

Certifications:

Not Applicable

SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

M3-Brigade Sponsor VI LLC

Signature:	/s/ Mohsin Y. Meghji
Name/Title:	Mohsin Y. Meghji, Authorized Person
Date:	11/12/2025

M3-Brigade Acquisition Partners VI Corp.

Signature:	/s/ Mohsin Y. Meghji
Name/Title:	Mohsin Y. Meghji, Authorized Person
Date:	11/12/2025

Mohsin Y. Meghji

Signature:	/s/ Mohsin Y. Meghji
Name/Title:	Mohsin Y. Meghji
Date:	11/12/2025

Exhibit Information

Exhibit 99.1: Joint Filing Agreement, dated as of November 12, 2025, by and among M3-Brigade Sponsor VI LLC, M3-Brigade Acquisition Partners VI Corp. and Mohsin Y. Meghji.