I have been following a professor whose research I really like. To simply illustrate the impact of his research, let me quote a quote from Quanta Magazine:
[He] says he usually gets two responses: “You’ve opened up a whole new theory, and you’re an idiot.”
We have exchanged many emails, and I have nailed my proposed research to the point where I believe that it suits his research very well. I am really satisfied with this.
However, I lack 5 points in TOEFL to reach the minimum requirement of this school. So I have to apply to other professors in other schools. Because he has opened up a new theory, other professors research doesn't have that much in common with my proposed one. I have no complain about that, and I think I would still be happy to work on a research that deviates from my proposed one. The next professor who has research similar to my proposal, has refused me because he doesn't have intention to admit more student this year (but he says he will be glad if I apply next year).
Q: If I really want to work on this research, can other professors advise me well? In my knowledge, I also need to work for them, to enrich their research, so chances are that I have to work on a different research. And if I do have to change my proposed one, which one is more advantageous, accepting it or waiting another year to apply? It's kind of a shame to spend a whole year preparing for grad school, then suddenly have to wait for another year; but I can deal with that.