Yes, if the RAR contains a file that's 4GB in size (or larger), you'll need to extract it to an NTFS drive.
If you only have 1 drive (and it's not NTFS), you can convert it to NTFS without losing any data.
Open up a command prompt window and type:
convert c: /FS:NTFS
If you want/need to convert a drive besides 'c:', use a different drive letter!
i.e.
convert d: /FS:NTFS