I would be hard in today's competitive residencies to get one 6 years after graduating. Not impossible, but its really going to depend on what kind of job you are currently doing. IE if you are already at a job doing resident like work, you would have a chance at getting a residency.....but then if you already had a job like that, you probably wouldn't be applying for a residency. As for how hard it would be, that would depend on how much resident like work you are doing in your current job. The majority of new grads, and probably a vast majority are your competition for residency, and they being fresh out of school, they will have an advantage over you in getting the residency. You will need to have something above and beyond the new grads, to beat them out of a residency.