66 with a stack.

PokerStars No-Limit Hold'em, 13 Tournament, 50/100 Blinds (4 handed) - PokerStars Converter Tool from FlopTurnRiver.com

BB (t1980)
UTG (t1732)
Hero (Button) (t3490)
SB (t1798)

Hero's M: 23.27

Preflop: Hero is Button with 6, 6
1 fold, Hero bets t300, 1 fold, BB raises to t1980 (All-In)

Villain is a multitable SNG reg but was playing very strange this tournament

Hero?

Raise a smaller amount. As played, fold.

Multitable reg? Quick fold I think. It's a good idea to raise against them, but if they come over the top on you, they pretty much have something good.

I agree with the others, 250 to go and fold to the shove considering the read that you have on opp.