Hey,

The duration of the course depends upon the type of course you are going for in the field of Graphic Design

There can be four duration that you can choose,

-Certificate course in Graphic Design for a duration of 11-12 months

- a diploma degree of 15 months or more

-an undergraduate degree of 3 or 4 years.

It's upto you which you have to choose to pursue.

More duration of course more knowledge and hence more chances of excelling in that particular field.

Hope that helps

Thank you