Remember RAID10, RAID50 and RAID60 are technically RAID on RAID schemes...
eg RAID10 is RAID 1 of multiple RAID 0 arrays or a RAID 0 of multiple RAID 1 arrays. (depending on your controller/software)
likewise, RAID50 is a RAID 5 of multiple RAID 0 arrays.
Using your example, with 2x TB and a 1x 4TB drive, you could technically create a RAID 0 of the 2x 2TB drives creating a 4TB RAID 0 array, then use that as a member with the other 4TB drive in a RAID1 array.
Or you could create a RAID 5 using the 3 drives, with a spare 2TB on the third drive for something else.
** Disclaimer, it depends entirely on your controller and software setup you are using.