One, you are assuming a lot of things. I was not born in India. I am in the process of getting the green card no matter how far fetched the odds are. I am extending my internship at my native medical school so that i can do an year of internship in USA (which as far as I know equates to work experience).
Secondly, I know the statistics. I know the number of people that apply for neurosurgery each year and get rejected, that is the reason why I have backups. I have never said that I WILL get into NS, if I do, well and good, if I dont, I have other specialties that are not so competitive.
Third, I assume that your intentions are to show me the reality, but what makes you think I have not considered every bad scenario that can ever happen.
Fourth, optimism trumps pessimism
I'm not for optimism or pessimism but realism.
I hope you the best OP, I really do, but please realize that for many IMGs there are no "specialties that are not so competitive". Even FM and psych and PM&R (to take a few examples of supposedly non-competitive specialties) are "competitive" for many IMGs. It really depends on what you get on Step 1, 2CK/CS, if you get a green card, how you interview, how you fit into American culture and society, etc.
All this is on the background of every year more and more homegrown American med students are graduating, yet residency spots aren't increasing enough to match the number of American med students graduating each year. At least that's what I hear, but I haven't verified it myself.
In any case, the worst case "scenario" is you don't do well on the USMLEs, you don't get a green card, you don't interview well, etc., and (unfortunately) you don't match to anything in the US. If that happens, then hopefully your "backup" plan includes working in your home nation.
At this point, yes it's "possible" you could match into neurosurgery, but it's just as "possible" you could not match into anything at all. Both doors are currently wide open for you, and you could walk through either door, depending on your USMLEs, green card status, etc.
For example, you mentioned getting an internship in the US. But is that already decided? Isn't that why you are posting and asking about what a transitional year is, because you are trying to figure out what to apply to (i.e., you haven't yet been accepted to an internship in the US)?
Again, I'm not trying to discourage you. But at this point from what you've told us, it sounds like you have a lot of good hopes and dreams (which again I hope the best for you OP). But the problem is there doesn't seem to be any tangible, hard, concrete reasons why any of this will necessarily pan out for you. As far as I can tell, you haven't secured an internship in the US yet, you haven't taken your Step 1, you haven't taken your Step 2CK/CS, you haven't gotten a green card, etc.
In other words, OP, you may have a lot of potential, but none of your potential has been realized yet. That's not being harsh toward you, that's just the reality.
Again, I hope you the best, I hope you get what you want, I hope you are one of the few lucky IMGs who match into neurosurgery in the US. But again it's a huge uphill battle and you started this thread not even knowing how difficult a transitional year was to match into. Nothing wrong with that, we all have to start somewhere. But I'm just saying a dose of reality might not hurt, and in fact a dose of reality might even help you better face the very big challenges ahead of you. If you know how tough it's going to be, then hopefully you'll fight all the more for it. Good luck OP!