How can I accede/get a specific column from NTuple?

Hi experts!!
During my run, I store all my data in several NTuples.
At the end of the run, I need to accede to these columns to make some calculations.
How can I accede/get a specific column from specific NTuple??

Thank you in advance.
Best, Dayron.

Save data in Root file and open the file by Root