In plain English
FAR 52.247-6, Financial Statement, is a contract clause prescribed at FAR 47.207-1(e), most recently dated Apr 1984. The complete official text is reproduced below, verbatim, from GSA's published FAR source files.
Its text contains no sentence requiring insertion into subcontracts; see the flowdown section below for what that does and does not mean.
Does it flow down to subcontracts?
No flowdown mandate found in the clause text
We scanned the full clause text and found no sentence directing the contractor to insert this clause into subcontracts. That is a statement about the text, not legal advice: a prime contractor may still flow terms down contractually, an agency supplement (DFARS, VAAR, …) may add requirements, and clauses listed below (if any) may order this clause into subcontracts from the outside.
Where it's prescribed
As prescribed in 47.207-1(e), insert the following provision in solicitations for transportation or for transportation-related services to ensure that offerors are prepared to furnish financial statements:
Prescribing reference: FAR 47.207-1(e).
The official text, verbatim
As prescribed in 47.207-1(e), insert the following provision in solicitations for transportation or for transportation-related services to ensure that offerors are prepared to furnish financial statements:
Financial Statement (Apr 1984)
The offeror shall, upon request, promptly furnish the Government with a current certified statement of the offeror’s financial condition and such data as the Government may request with respect to the offeror’s operations. The Government will use this information to determine the offeror’s financial responsibility and ability to perform under the contract. Failure of an offeror to comply with a request for information will subject the offer to possible rejection on responsibility grounds.
(End of clause)