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I‘m 15 and have a rating of 2600... do you think I can become a GM?

“... It is all too frequent that a wrong evaluation is made of what a talented player can achieve. ... Most players have the potential for a certain level; once they have reached it they can only make further progress with a great effort. ..." - from a 12 page chapter on becoming a chess professional in the book, Luther's Chess Reformation by GM Thomas Luther (2016)
lichess.org/forum/general-chess-discussion/i-want-to-become-a-gm?page=2
Your ability to even try boils down to money and free time. In some places with a lot of tournaments nearby (Europe is tiny) it will be cheaper. You probably have a few years left in 'child time' and that's a good thing; if you haven't achieved it before you have to start living in 'adult time' the dream is pretty much over and you have to wake up.

Nobody can say for sure whether you'll make it because nobody knows the future, but you could try getting some norms for the IM title and see how easy or hard it is. You need the trifecta of time, skill, and money; figure it out.
Lichess rapid rating calculated from 13 games with rating deviation just barely below 110 is not very relevant for this question (and even less so the bullet rating). FIDE ELO of 1879 is probably much more important. I knew few people who were around this level at 15 and earned the GM title later (and, of course, many more who did not). So it may be possible. However, that was 35 years ago, it may be much harder today when the trend is that players reach high levels much earlier. After all, according to FIDE database, just in Germany there are 145 players born in 2008 or later with higher ELO than yours - and total of 77 active GMs (regardless of age).

Another important question is if you would really want it; such goal would require dedicating a big part of your life to chess and sacrificing a lot to it.
@JuicyChickenNO1 said in #4:
> Europe is tiny

It has a couple of hundred thousand square km more than the U.S.; try a road trip from Gibraltar to the North Cape in Norway to start to get the feel of it.

What you probably mean is that it has a much larger concentration of major cities, and that chess is much more deeply rooted in its culture than is the case in the U.S.; the density of tournaments is therefore much higher.

But tiny? Nope. We ́re bigger. :)
@JuicyChickenNO1
That isn't true, you can be an adult and still practice and still become something. Just because you have a professional life and private life doesn't mean the time for your hobbies disappear. At least not if you are reasonable using your time, you should always have at least some time. And if you choose to watch TV for all your time, in the process neglecting your practice; that is your fault that you don't improve.
@ThePlayzPaidOff said in #9:
> At least not if you are reasonable using your time, you should always have at least some time.
You're gonna remember your post sometime after you get your first job and you're gonna think "oh, so this is what he meant."