Thanks alot for your kind reply, it would be really greatfull if you can send and official link stating the same information as i get confused after talking to a cic agent, who told me that if i applied from inside canada so they supposed to get my passport in ottawa office for stamp.Yes, you can submit it to the VAC in the country you're visiting. Or it may be possible to mail your passport directly to the visa office if it is allowed for that country.
Do keep in mind the time required for passport transmission + your actual stay in that country before you submit your passport there
And i planned to stay for two months in Pakistan that's why i was thinking of this option. Also, i checked like its not possible to send passport internationally.
I really appreciate your time and effort. Thanks alot.