welcome to Stackoverflow. To increase chances of getting an answer, post a reproducible example. A reproducible example consists of a minimal dataset similar to one you're using (or use dput() on your data and post the output) and an example of code that you have that isn't working.
To your post, the reason you get that error is because getSymbols() uses auto.assign = TRUE by default. This means that whatever data you download gets saved to the environment as its ticker symbol. However, R objects are not allowed to start with a number, so these objects are saved using backticks like so:
`1475.T`
So if you want to access the object, call it using backticks
View(`1475.T`)
print(`1475.T`)
Or preferrably, set auto.assign to FALSE and save the result to a variable.
library(quantmod)
iShares.Core.ETF <- getSymbols("1475.T", auto.assign = FALSE)