suppose your data is names "data"
#X1列的值位于{1,2}范围内
data[which((data$X1==1)|(data$X1==2)),]
#X5列的值位于{2,5,6}范围
data[which((data$X5==2)|(data$X2==5)|(data$X2==6)),]
#X1列的值位于{1,2}范围内,X5列的值位于{2,5,6}范围内
data[which(((data$X1==1)|(data$X1==2))&
((data$X5==2)|(data$X2==5)|(data$X2==6)),]