Can anyone guide me on Saudi Arabia's visa issue ?

I am a Pakistani and I have been offered a job in saudi arabia as a junior project manager since im a fresh graduate holding B.Engg Electrical and Electronics. I am not sure whether I will be granted a professional visa or I will be hired on a labor visa. I want to ask whether i should go to KSA on a labor visa? Can i change it later after arriving in the kingdom? What are the disadvantages and problems i will be facing out there?

I answered your other question. First, you will know the category of the profession on the visa before you submit your passport for stamping the visa, hence it will be known to you before hand. Secondly, do not accept a visa with the profession "labor" on it it as you will have difficulty in everything such as a driving license and bringing your family later on. Changing the profession later is not easy anymore, it takes time and costs a huge amount of money paid to the middle men who can expedite the issue but the salary you have been offered is such that you will not have the kind of money demanded to change profession in a short period.