Hello, I am new here. I have certain numbers of duplicates for each Probe ID (approx. 45000) in one column and its samples data values in others 'n' columns(approx.. 230 columns) in excel sheet . I need to do aggregate/average of it with single Probe ID for each data and its respective values. How can I get it using in R?

Normally you would not have the data in Excel, but instead in an ExpressionSet that was generated by using the oligo package to read in, summarize, and normalize the data. You can read the oligo vignette for more information about that.

But if all you have is the data in an Excel workbook, you could use something like openxlsx to read the data into R, then you could use avereps from the limma package to average the replicate probes