From your earlier questions, it is clear this one is a continuation of what you asked previously. You should not be creating multiple questions, all asking the same thing, in slightly different ways. Especially, when you are not formulating your questions clearly, as is the case with this one.
To answer this question directly: yes. If you read doc page on frd you will see frd object is just a vector of complex numbers representing system response at specified frequencies.
For any given magnitude and phase, the complex number is mag*exp(i*2pi*phase/360), where phase is angle in degrees.
Whether phase is 300 deg or -60 or 660 or -420, the resulting complex number will be the same.
So, to answer your question, yes, you can represent gain of 5 and phase of 300 deg as an frd object.
Your real question though is whether you can somehow get back the value of 300 deg (and not -60 deg) from that object. The answer is no, if you use standard functions like bode.
So to really answer this question and the other two you asked on the same topic - if you need custom behavior, write your own custom code in MATLAB to do the computations.
