conditional mutate across multiple columns

tidyverse
2

Without a reprex, only a sketch will be offered

rawdata %>% mutate(T1 = case_when(
                         T1 < 10 ~ NA,
                         T1 >= 10 & T1 < 33 ~ T1,
                         T1 >= 30 ~ 33)
                  ),
           mutate ... [etc]

has greater legibility. Rather than repeating this code block for all six numeric variables, however, make it into a function and use mutate_if [numeric].