You already made you mid for civic 2001 n you want to get info about civic not the suggestion of car, title didn't suite the content.
Civic is not a fuel efficient car
1= No
2= Auto 8-9 if not well maintained 6-7, manual 11-12, 100-140 cng 55L
3= 2001-3 cat eye exi manual ll come in you budget as you are in karachi
in karachi in 775 you can find 2006 shape city idsi 1.3 manual 2-3 pieces touching, which ll give you 13-15 kmpl n upto 220km on cng, cheap maintenance as compare to civic, but you dont like city, best of luck