With a 1x9, your chainline should be as close to middle of the cassettte as possible. Or, if you know you won't spend much time on the biggest cogs, then over a bit is probably OK if you can still get it up on the big cog if you need to.

If sixth gear is the quietest, then that's probably the chainline too.

A quick way to check your chainline is to take the chain off and drape it over the chainring while hanging the bike by its front wheel. Kind of like a plum bob. To get more accuracy, put something on the left crank to balance the weight. You get the picture. Right?

I can't tell from the picture, but is your chainring bolted inboard or outboard on the crankset? If it's bolted on the inboard side, move it to the outboard side. That will give you a few millimeters without spending a penny or impacting the Q factor of your crankset. The only reason that chainrings are designated as inboard or outboard is for people with front derailleurs.