I would guess you tune it exactly like a guitar, only an octave down. I don't own one though, so I suppose I could be wrong.
Six-string basses are usually tuned (low to high) B E A D G C. The strings of a normal four string bass are sorta in the middle with an added string below and above. Most will prefer to tune the first string to C as indicated, so that all the open strings are tuned a P4 apart, but some opt to tune it to B to mirror a guitar's second string (an octave lower, of course). Hell, if ya wanted to, you could tune in (low to high) B E A D Gb B so that it has the same relative tuning as a guitar...
It can be whatever you want, and I'm sure some people prefer two higher strings, but five string basses often have a lower string added - a six stringer is usually just that with a higher one...
Basically, all the strings of a regular guitar, except for an octave lower, and now high E string, and an extra low B as per a 5 string bass. Or at least that's how I'd tune one, so it's B E A D G B
yes you can of course tune it however you want, but the standard tuning for a 6 string is B E A D G C
I own an ibanez 6 string bass. I tune it B E A D G C . It doesn't change any of the scale patterns that way. Makes it much easier IMO
A lot of those Jazz folks go for E-A-D-G-C-F so that they can do all those chords, arpeggios, solos, etc. etc. But like they said earlier B-E-A-D-G-C is your standard 6 string set up.