Regarding for moving to bulgaria from pakistan with in a 3 to 4 months

With this I can't help you. I never been in Pakistan. Maybe some more specific questions .

Bulgaria is a member state of the European Union - with this your rights are granted as the same as in any of the member-states.
Bulgaria has wonderful climate, 4 seasons, kind and nice people, and everything is cheap. You will  not feel like in a foreign country once you can shop in all popular world-wide supermarket chains or have lunch in McDonalds, SubWay so on.
And regarding any further questions you can easily contact me as a Bulgarian lawyer I may be a help.
[email protected]

Hope that was useful and helpful.

Best wishes and good luck!

Thanx and me move there may be in January or February so kinly tell me which city is better for me like in monthly expenses and for job. Is there any odd jobs like uk. And me living in pakistan doing job of mechanical engineer and my monthly earnings are 500£ kindly tell me that bulgaria is better option for me in future or Pakistan as you know now a days pakistan is not a secure country for lliving here is many problems llike load sheding of electricity and utilities are expensive no security and etc

Sorry to say,Bulgaria is not a cheap country especially when you are having family.
As a non eu members you have to have a private health insurance.
It is not easy for to get a job here.
When applying for the visa,you will have to have a health insurance,bank account statement around 1000-2000 euro each,for you and your partner,don´t know about the children.The contract for the rented or bought properties and someone who can help you with the translation.
With 500 pounds,you wil not be able to survive here in Bulgaria.
The best is,when you are still planning to move to Bulgarian,try to get a job first before you move to Bulgaria.
Wish you lots of luck