r usuń numer wierszu wyższy niż
df[!rowSums(df[-1] >7),]
# a b c
#2 6 6 5
#3 99 3 6
#4 7 4 7
#6 9 6 3
Glorious Gharial
df[!rowSums(df[-1] >7),]
# a b c
#2 6 6 5
#3 99 3 6
#4 7 4 7
#6 9 6 3