Recover database using backup controlfile

Hi guys
I have doubt in backup sceneries

For example I have lost my control file,and some of the datafiles and all Redo logs. So I restored control file from last backup and data files from inconsistent backups and Redo from some other backups

Now how control file will identify upto which SCN it has to perform recovery,since all the SCN are different in datafiles and Redo also is old.

Thanks is advance
Syed

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