What is the ruling on obtaining a scholarship by defrauding the GPA requirements, and benefiting from its money, and the money received from the salary after graduation? And what should be done about that?

It is impermissible to benefit from a scholarship for one who does not meet the conditions of the granting institution, because the Prophet, peace and blessings be upon him, said: "Muslims are bound by their conditions." If you deceived the granting institution, you must repent and return the money to them, unless they agree to your entitlement after you inform them of your true situation. As for the salary of the job thereafter, its ruling depends on your fulfilling the duties of the work entrusted to you, and it is not made unlawful by having obtained the scholarship through illicit means.