Am I allowed to apply for temporary residence permit for graduate looking for work or planning to establish an economic activity before I graduate from university?

Yes, you are. Remember to include in the justification, next to the indicated purpose of your stay for looking for a job, that the graduation will not be in a few months so that this will be taken into account in case of a request to complete some documents or issue a decision. If the deadline for the graduation is delayed and you want to suspend the proceedings, you can do so, but remember that your stay will not be legal after the expiry of your visa, visa-free travel or your residence card.