I was offered a full tuition scholarship to Vanderbilt last year. I was out of state, non URM. I didnt have to apply for it separately, they notified me about a month after I got accepted that they were offering it to me. I guess it was based on merit, because they didnt know anything about my financial situation when they gave it out to me. I know Vandy also gives some scholarships for URMs.
As for the merit based scholarships, i have no idea what they are looking for specifically, the award letter didnt really talk about the selection grounds.
good luck, i was impressed with vandy