hello
according to the mark scheme
R
towards centre) = mgcos(x) - R = ma
The centripetal acceleration acts towards the centre of the circle, and the reaction force is in the opposite direction?
I think you are making the mistake of forming a statics-like equation, since if you rearrange the above formulae it would appear that R and ma (cenforce) are in the same direction.
When you look at problems like this, consider the reaction force and the force of gravity, are experiencing centripetal acceleration, don't consider it as a force. Think back to an M1 dynamics problem, you wouldn't make that mistake there.
I realise i havent explained this too well but if you have any questions just quote me