im a junior soldier would i have to join Adjutant General’s Corps to become a rmp soldier

Good Afternoon Owen.
Since you’ve said you’re a junior solder, that means you’re already at AFC Harrogate, which also means you’ve already picked the Regiment/Corps you wish to join.
Yes the RMP are a branch within the AGC, aswell as the SPS, GSPS, ALS, ETS, MPGS and Provist Branch.
You have to be 17 years and 6 months old, need the required grades and pass the Advanced Police disclosure checks.
As far as I’m aware, you can’t pick the RMP whilst at Harrogate, it’s an adult entry Job Role but hopefully one of the RMP representatives will also reply back to your question.
Hope my response helps!

Ok thanks