[Depasqualethepolymath]

Can C6H5NH3 be produced from phenylamine ?? I couldn't find a way since the only NH3 present in a benzene ring is as a transitional state when producing phenylamine..

[Babcock_Hall]

With all due respect, you said something that is going off on a tangent.  I agree that transition states have only a fleeting existence, but they don't have anything to do with this problem.  If you simply draw out the putative reactant and product, you may find a simple answer to your question.

[Depasqualethepolymath]

The question is about a mechanism on how to produce C₆H₂Br₃NH₃ from benzene

[Babcock_Hall]

Welcome to the forums.  I see that the starting material and product have both changed from your original post.  According to the rules of this forum, you should provide your attempt at an answer before we can help you.  A good place to start is to draw the starting material.  So far you have not specified which isomer you need, and the answer will depend on this, almost certainly.

[Depasqualethepolymath]

Benzene ring --> C₆H₂Br₃NH₃
I am being asked on how to arrive to the product from the reactant and I cannot find a suitable mechanism that's why I asked what I asked before...

[Babcock_Hall]

I wouldn't call what you were asked to produce a "mechanism" (which involves metastable intermediates and possibly transition states); I would call it a "synthetic pathway."  As I indicated above, the compound you have indicated is your synthetic target exists as a number of isomers.  Were you given a structure or just the molecular formula?  If you were only given a formula, then the question will have more than one possible answer.  I am attaching a document showing three isomers, just to illustrate what I mean.  In any case, you must show us what you have tried (even if it is wrong), before we can help you.  That is a forum rule.