You can leave your hair, tie it into a ponytail or also tie it into​ a bun.

The rubber band must be plain without any stones or metal pieces attached to it.

And you shouldn't wear any kind of clips and braids are not allowed too.

Dear student

Yes you can tie your hair.As far as I know hair bands or any sort of clips and accessories are not allowed. But rubber bands are not allowed. This means you have to use a thin girdle to tie your hair. 

Hope this helps

All the Best !!!