dragi moj ti si jedan od retkih koji ostaje pravi prijatelj kada dodjes u evropu obavezno mi se javi do tada cu dobiti i vizu pa mogu i ja da dodjem kod tebe da te vidim
My dear, you're one of the few friends of mine who remain faithful. Don't forget to call me when you come to Europe. I will get the visa by then, so I could come to see you at your place.
Remarks about the translation
When somebody says "obavezno mi se javi" ("call me for sure") he/she wants to remember someone to call him/her. That's why I translated it with "don't forget to call me".
Hi Maki,
This line is weird:
"you're one of the few ones who remains a true friend"
I'd say:
"you're one of the few true friends I still have"
or
"you're one of the few true friends (of mine) that still remain"
or even:
"you're one of the few friends of mine who remain faithful."