Используйте sub
в случае нечувствительного к регистру режима:
output <- sub("\\s+Bangalore$", "", input, ignore.case=TRUE)
output
[1] "TCS"
[2] "Wipro global"
[3] "Bangalore consultant India private limited"
[4] "Infosys"
[5] "systems bangalore pvt ltd"
Данные:
input <- c("TCS bangalore",
"Wipro global Bangalore",
"Bangalore consultant India private limited",
"Infosys Bangalore",
"systems bangalore pvt ltd")