Firstly, NBP offers permanent position whereas, senate offers internship which does not guarantee any job after completion. Secondly, seats allocation in senate are very few, which means more competition and any mistake take you out of competition, whereas in NBP, they select the whole batch consist of I think 80 to 90 candidates. Thirdly, this is for me only, test of senate is in khi and NBP is in sukkur which is my home town. Lastly, paper is quite rigorous of senate i.e mcqs and eassy exam. whereas in nbp, its just mcqs.