What problem to have 6 LK?
ST: 1 or 2. Depends on what weapon you use, if 5 ST, then 2 + 1 buffout, if >5, then 1 and x2 buffout, so it's not logical to waste points on strength, but only if you're HtH character.
PE: max 8. Under x2 jet it'll be 10, if fight isn't serious (PvE) you don't need PE much.
EN: 6. For toughness, with buffout it'll be 9 or 10 with 2, against criticals.
CH: 1.
IN: 7 If ST=2; 8 if ST=1. (all points that left after all other SPECIAL + Small Frame trait, if without trait, then 6/7 IN)
AG: 7. It'll be 9 or 10 'cause of 1/2 buffout, if 9, then 10, because of nukacola.
LK: 10. For criticals and against criticals.
If you want your LK only 6, then you have 4 spare points left, if you don't like to be sickly, you can spend it on your ST.
Edit:
SPECIAL in case of 5 ST (2 base ST) and x1 buffout, x1 cola and x2 jet:
S 5
P 10
E 9
C 1
I 7
A 10
L 10
If you're BGer and have 1 base ST, but x2 buffout and x2 Jet:
S 6
P 10
E 10
C 1
I 8
A 10
L 10
What a reason to have less than 6 LK?
Only if you're leader build and want to have alot CH.