Welcome to the Bunnings Workshop community @mel-reservoir. It's wonderful to have you join us, and many thanks for the question about your Buffalo lawn.
I hate to be the bearer of bad news, but that lawn looks relatively devoid of any signs of life. Buffalo can tend to brown off a little during the colder months, but not to that extreme. I'd hazard a guess that due to it being laid in June, it never was able to establish and died off. Grass goes dormant in the cooler months and doesn't particularly like to be laid then, and it certainly won't establish until it warms up. We only sell grass in Spring and Summer partly for this reason.