The registration date for this year is over,and only n1 and n2 are opened.

The next one on 2022 July.
https://www.jlsm.org/

You may keep track here between nezt year March to April for the registration.
Main sites are KL and penang. There is also ipoh sabah and sarawak, but was cancel for these sites due to covid

Hopefully next year all test sites and all levels will be opened.

N5 is the lowest n1 is the highest.

Most aim for n2 as that's the minimum needed for applying jobs.
N5 to N3 are levels for self evaluations.

I haven't took n1 yet, not sure how is it like. But the numbers of candidates at KL test session are often below 100. While n5 has 200 to 300.