Rita form 37 what does column 6 mean?

It is asking you to enter the information if you had winnings from gambling---did you win money at a casino, etc.?  If so, you are supposed to enter the amounts of your winnings.   If you did not win any money from gambling leave it blank.

As xmasbaby0 mentions if you lived in and/or had gambling winnings in a taxing RITA Municipality then you use the date of winnings in column 6 to report when you earned that gambling income.  This is usually from a form W2G.