Is yo baby yogurt okay for 6 month olds?

yes ma'am! get the full fat version

I wouldn't - way too much sugar, read the label. Regular full fat plain yogurt with no added sugar would be a much better choice.

When my kids were small it was recommended to stay away from outside dairy (meaning only breast milk or formula) until 9 months at the earliest.

I would skip it. There are so many foods to introduce, start small with single ingredients, with no added sugars, i.e., fruits and veggies.

I personally didn't give my son anything until he was 9 months, but I don't think you have to worry about it he might not really eat it right away anyway. I would experiment but of courst don't give too much for the first try.
good luck!

I wouldn't yet. A great site for infant feeding and a list of easy first foods can be found here.