indirect speech

First of all, I responsible for this project is incorrect.  Responsible is an adjective.  The correct sentence should be I am responsible for this project.

Secondly, has said is an unusual way to introduce direct speech.  The simple past verb said is much better to use.

You also have capitalization and punctuation problems in your sentence.

Direct speech (revised)

Carol said, "I am responsible for this project."

Indirect speech

Carol said (that) she was responsible for the project.

Issues about which Grammar Experts Might Disagree

-some would keep the verb present tense is responsible for...in indirect speech

-some would change this in direct speech to that in indirect speech

I hope this helps.