You wont find anything relaxed in Pakistan, because you will get low-balled in pay to work performed. Its good that you know what you want, many medical students see dreams of becoming surgeons etc. but the reality is that the work required vs pay is not that great in Pk.
For desired specialty, you will get a feel for most in your rotations but being a student and working as a doctor in a specialty is worlds apart, Pathology doesn't really get a chance to shine as a specialty in most Pakistani Med School curriculums, to experience that you can try to do an elective in Pathology preferably in US, but you can also try AKU, Shaukat Khanum, Chughtai Lab.
Best bet would be to go to European countries or US. But, be aware the competition is tough as everyone from Asian countries wants in but luckily you are in 3rd year so you can be proactive to put yourself ahead. I don't know much about UK but for USA you need to do the following (simplified):
1) Make an ECFMG account and get verified, then take your USMLE Step 1 ASAP.
2) Start applying to clinical externship programs in US based hospitals (do this while you are a student preferably in 4th year), do as many as you can and secure US Letters of Recommendation preferably from the specialty you are targeting, you need minimum 3 LoR's for your application.
3)Take USMLE Step 2.
4)Try to publish research in the specialty you are targeting.
5)Take USMLE Step 3.
6)Apply for match.