I started work with a company when I was a fresh graduate 6 years ago but left after a month because I felt I wasn't competent for the position and there was some family issues ongoing. 6 years on, I am ready to re-apply to this company but is dealt with a dilemma. I am required to indicate if I have worked for the company before and if so, what was the reason I left. I need some advice on whether I should declare in the application that I left the company prematurely 6 years ago or leave it out?

Please help!