How to get cambodian visa being in Pakistan

If you have a job offer then it is up to your employer to arrange the visa for you.
If you want to get a visa yourself, contact the Cambodian Embassy in India for information.

Thanks for your reply. I have contaced the Cambodian Embassy in India but they refused to process visa application through mail. I need to be there to process my applicqtion which is near to impossible having short time.
Can you please provide some more info about how my employer can arrange visa for me. Do I need to send them my passport??

Contact your employer directly and discuss this with them. You will not get a visa quickly, it all takes time.
Have you considered coming to Thailand or Laos and processing the visa there.?

Are you sure you cannot get visa on arrival. If Pakistan is a member of ASEAN then you can get a visa on arrival.

You must get an invitation/sponsor letter promising work and information/sponsor letter about your job responsibilities, also they must guarantee, your stay for what ever period of time. You also must have a return ticket
to Pakistan.
I have heard it is possible (once you have the invitation/sponsor letter) to apply at the Cambodian Embassy in Bangkok, and then fly onto Phnom Penh from there. There are lots of different (yes and no) answers about crossing by land border.
I would contact the employer and ask them to go to the Cambodian and or Pakistan embassy here in Phnom Penh to guarantee the correct procedure to obtain your visa, if they want you to work for them it should be no trouble.
Below from Official Cambodian Embassy site:
Applicants from Afghanistan, Algeria, Bangladesh, Iran, Iraq, Pakistan, Saudi Arabia, Sri Lanka and Sudan, except for those employed by the UN, IMF,WORLD BANK, ADB and other International Organizations, must provide the following:

Letter of Sponsor from his/her company, local NGO, school
Return air ticket to and from Cambodia
One photocopy of Alien ID Card, student ID card

coming from Pakistan  im from Australia but you need to get a working visa if you are going to work here and the bribes are huge I have been living in Cambodia for 3 years now on a normal visa not a tourist visa  best you apply or see online or get a normal visa at phnom penh airport on arrival but you cant get a working visa at the airport but getting a working visa is big dollars just come on a normal visa $25 per month or $290 for 1 year  don't tell them you are going to work here