Each skip has their pros and cons. I don't think you can ski Y10 considering your situation, but you could try.
Y9 -> Y11: if you can reaally cram some GCSEs in a year, but you'd need to sacrifice choice early. I'm not from UK, but for me schools were willing to consider this? It'll be tough though, going in the middle of a course for GCSE. My case is different as I was in a different educational system.
Pro: you still have a year to prepare for 6th form, while skiping the easier parts of GCSE. The least amount of catch-up needed.
Cons: Going to the middle of a course could leave you with gaps, and socially the GCSE year would've bonded for at least a year in most cases.
Conclusion: Not very good, although in some cases, maybe (for example if you're an overseas student just trying to take a few GCSEs in 1 year, this has been done many times). You'd be dvncing ahead in many subjects.
Y10 -> Y12 is effectively going from 1st year GCSE to 1st year 6th form. So effectively sixth form a year early. I've been offered this skip by multiple schools in the UK.
Pro: start 6th form a year early, the serious uni prep a year early, and the transition from school student to young adult can begin immediately. Sixth forms are used to taking students of different ability and background from GCSE to A-level/Higher, as Y11 -> Y12 is a common period to switch schools. Socially you'd be regarded as a new student and they won't reallly care too much about age. I have the most experience with being offered this, so I can advise you.
Cons: You may skip over lower-level qualifications like GCSE Math and English, although this would be less of a problem in the Scottish system, because they have a much stronger focus on Highers. Restricted choices and less time to decide ppost 16 qualification.
Conclusions: This may actually be good, depending on which system you are in.
Y11 -> Y13 ... you'd need to catch up half of the A-levels which is significant, if not daunting. You may need to be serious from day 1 aand sacrifice things.
Pro: at least finish your lower-level qualificaations and get thaat foundation sorted.
Con: potential socil issues from moving into middle of qualification, daunting catch-up, but if you reaally want... it might work but you have to be reaal serious and have a strong plan, think real far ahead.
Conclusion: Not great, although if you already know so much of the content you might make it?
Y12 -> Uni ... you can simply take everything a year early and then go to uni.
Pro: Everything finished like the others, except you go to uni a year early. Socially probably the best. In uni people don't care too much about age. In other educational systems, graduating early is common. For example in America, you can apply to uni as junior. Carnegie Mellon has a special admission track for high school juniors (Year 12).
Cons: I guess some under 18 restrictions, although if you skip you'd probably be faced with them anywaay.
Conclusion: i guess this is good.
The takeaway: if you skip, ideally the transition should be seamless, for examples A-level to uni but you took your A-levels a year early and you're not deferring entry. Alternatively, entering sixth form/college a year early from Y10 (although not haaving the lower-level qualifications my bite you in the back, you could take the GCSE math and english in sixth form/college like some do).
If you really wanted to skip,
@*LifeHappens* ideally, Y12 -> Uni (take all A-level a year early), or next best, Y10 -> Y12 (but need to solve the issue of skipping over lower-level qualifications).
The other skips are more daunting although you can consider them.