From your facts, it is unclear whether what you are calling hearsay, is in fact hearsay under the legal definition.
In general, an arrest warrant can be filed if the prosecution has probable cause to believe that a crime has been committed, and that you committed it. An indictment can be based upon that same level of proof. Hearsay is admissible in the Grand Jury. A conviction would require the prosecution to establish your guilt beyond a reasonable doubt, a substantially higher level of proof, and Hearsay would generally be inadmissible unless it met a specific evidential rule permitting it. Consult with an experienced criminal defense lawyer admitted to practice law in TN as soon as possible. Good luck.
This information is offered for informational purposes only, as I do not practice law in your State. It is not intended as legal advice and you should not rely upon it to decide how to resolve this issue. No Attorney-Client relationship is intended or established by this response. You are faced with a situation where you need to consult with an experienced defense lawyer admitted to practice law in your State before you make any decisions as to how to resolve this issue.
It depends. If someone told them that they observed you dealing meth, then that's probably enough to indict. If that person doesn't appear at trial, can the cop say "so and so told me he was dealing meth." No.
Edward J. Blum
When you say that the federal indictment is based "just by what somebody told them" I assume you mean that someone told the federal government that you were dealing meth. If that's the case, then it depends on how that person knows that you were dealing (assuming it's true). If the person saw you dealing, or helped you deal, then it isn't hearsay, it's just testimony. They can convict you based on the testimony of witnesses.
If, though, it's just that person saying that they heard you were dealing from someone else, the government would likely have to call that someone else to convict you at trial (though that evidence can be introduced in the grand jury to get an indictment). There are nuances to that, but this is the general rule.
So, the answer is that whether the evidence is admissible depends on exactly what the evidence is.
And, I hope this is obvious, if you've been indicted for dealing meth, or, frankly, for anything else, please get yourself a lawyer very quickly.