I would definitely try to retake your GMAT, and thoroughly prepare for it. A 450 score puts you in the 21 percentile range, which means that most other test takers, by far, scored better than you. This does not bode well for being competitive.
If you have something clearly amazing about the rest of your profile - such as stellar work experience, or something unique about your background, there is a possibility that ad comms would overlook your poor GMAT score - but barring something amazing, 450 does not look good.
I would definitely try to retake your GMAT, and thoroughly prepare for it. A 450 score puts you in the 21 percentile range, which means that most other test takers, by far, scored better than you. This does not bode well for being competitive.
If you have something clearly amazing about the rest of your profile - such as stellar work experience, or something unique about your background, there is a possibility that ad comms would overlook your poor GMAT score - but barring something amazing, 450 does not look good.