Am I correct that får is a statement of permission (You may try.), whereas kan is a statement of ability (You can try.)? Sorry to split hairs, but my old grammar teacher would come back to haunt me if I didn't ask.
You cannot use må here. Basically today we only use må for 'feel' like in hur mår du, and in the set expression ja må han leva. When you say må in Danish meaning 'be allowed to', 'have to', that is får or måste in Swedish.