hmm ok..
But I am just curious to whether tutoring centres teach you things that you self-studying won't. For example, the various tricks to solve different problems. I mean surely if you want to state rank, you should be able to know certain problem solving techniques that textbooks don't explicitly tell you. All these textbooks tell you is solutions to problems, but nothing other than that.
That's the thing though, you shouldn't just be absorbing the solution techniques you read in books. When you come across hard problems you should bang your head against them for a bit and try to come up with clever ways of doing them yourself. Success or failure, this way you get a MUCH better feel for what sort of techniques work in different situations than if you are simply told a collection of tricks that worked for tutor X.
No collection of tricks will be exhaustive, and everyone has their own subtly different ways of thinking about concepts, so it is much more important to develop your own problemsolving skills. (And there are plenty of resources online, even just things like this forum, for asking about problems that particularly stumped you).
Whilst some (imo very few) state rankers might be able to reach a state of readiness simply by memorising/cataloguing a vast collection of problemsolving techniques from tutors and doing a billion past papers, the best students are usually the ones that think more actively about the material and try to prove things themselves / improve solutions themselves / etc.
As a bonus, this style of study emphasising creativity and problemsolving is much more enjoyable that a more rote approach, and if you start to enjoy and get engrossed in the subject, that bodes better for your success than any number of tutors.
P.s. I don't mean to discourage you from getting a tutor if you really believe it is the best move for you based on information from everyone, this is just my view as someone who SRd and tutored for years. If you do decide to get a tutor, just be thorough with your research, because a lot of private tutors/coaching colleges are quite mediocre.