@Mohamed Mohsin If you don't know how to solve a problem, try to find an easier problem that you can solve. If you don't know how to solve that easier problem, find even an easier one, and so on, until you arrive at a point where you are able to do something.
For instance, in your case, do you know how to solve
D^γ S(t) = S(t)
and if not, do you know how to solve
D S(t) = S(t)
and so on.
You should also ask yourself:
- Do I know anything about fractional differential equations?
- Do I know anything about the homotopy perturbation method?
Answers to these questions have nothing to do with Maple. Begin with investigating these mathematical prerequisites of your master's thesis. Coding and calculating with Maple will come only after you have positively answered those questions.