Mummy1234, may i know which neighborhood school that you want to send?
I suggest you look at Express stream- your kid will be more well taken of by teachers as compared to NA. Cos Express is suppose to be cream of the crop. Not the NA. I agreed with one of the EDMWers said NA used 4 years preparing N level and 1 year for O level. Trust me, it's a HUGE jump. Unless your kid can score min 85 pts for almost every subjects, chances of promoting from NA to Express is low.
Generally, principals won't want to take risk
With some tuition, your kid should have no problem catching up. NA has many many unmotivated, irritating kids. You won't want him to mix with them.