Hi Navyd, how lovely to have another overseas member. It's very interesting for most of us in the UK to find out how other people keep their chickens in different climates, and you'll certainly have our support from afar. What's it like where you live in Pakistan?
I think Tygrsek's advice about starting small is very useful. We all remember what a steep learning curve it is when you first get hens, we all made mistakes at first, so getting to grips with the basics on a few hens would seem a good way to start, if your livelihood didn't depend on it. Would you be wanting to hatch your own, or is there a source of supply locally if you want to use egglaying hybrids? Also I've heard that it can be difficult locating suitable food in some countries for hybrid hens bred to Western standards of heavy egg production, if that's the sort of birds you're looking for. Something else to sort out as well as what Chris says about finding local outlets for your eggs or birds.
anyway, do keep in touch and let us know how you get on.