She mentioned that she will call me later.

Solution

In reported speech, the future tense used in direct speech ("will call") changes to the conditional tense ("would call") when reporting. This maintains the correct sequence of tenses in indirect speech. she will have being called me later: This option is grammatically incorrect and does not fit the context of reported speech. she has called me later: This changes the meaning to present perfect tense, which is not suitable for reporting future actions. she is calling me later: This uses the present continuous tense, which is not appropriate for reporting future actions in indirect speech.