March time to register children to school?

I am not sure when the time to register children to school is. I called up a school to ask and I was told that need to go online website to register then print out the copy and bring to school. The website given cannot access at all, I was told that only able to access the website in March. Tomorrow is 1st of March does it mean I am able to check the website.

If you know the website does share with me. I check online and saw some mommy blogger mention they did both like go register in school and also register online. Do we need to do both? Can we just register at the school and not online, any advice from mommy that have register children in school.