data<-data.frame(NAMES=replicate(100, paste(sample(letters, 8, replace=T), collapse="")), AGES=sample(20:60, 100, replace=T))
head(data)

     NAMES AGES
1 oepefudt   21
2 ibmuaemm   49
3 mkockaqu   23
4 whyzomna   59
5 omqqtbsz   35
6 qnbmjmuf   25

sort(as.character(data$NAMES[data$AGES==max(data$AGES)]))

# Find the maximum age
max.age<-max(data$AGES)
# Which rows have the maximum age value?
ind<-which(data$AGES==max.age)
# Extract the name using the ind from above
persons<-as.character(data$NAMES[ind])
# Sort the names
persons.sorted<-sort(persons)
persons.sorted