Recommendations
A practical starting range for beef brisket in the oven is 300-360 minutes at 150°C. This page is built to answer the cooking-time query fast without burying the useful part under a long recipe story.
Use the clock as guidance only and confirm an internal temperature of at least 63°C when that safety target applies.
The result usually shifts most with weight, covered/braised vs dry roast, oven temp, so treat the range as guidance rather than a guarantee.