How many grades can I apply for when I learn hard pen calligraphy for the first time in grade four?

Level 4-6.

Beginners below grade three choose primary school for the first time (grade1-3);

Above primary school grade, you can choose intermediate (grade 4-6) for the first time;

Calligraphy lovers with calligraphy major or higher level can apply for advanced level (level 7-9).