Is it true you can only have ten ounces of protein on the ketosis diet?

In general you should NOT follow a diet unless you hired a professional person to make it for you. You can do better by studying books about nutrition so you know how to eat right. AFTER you have learned some general knowledge, then you can study this ketosis fad and see if it sounds healthful or wacko to you.

You need about 0.4 gram of complete protein per pound of body weight, which means 60 grams for a typical female and 90 grams for a typical male. For convenience you only count 6 grams per egg, 12 grams per glass of milk, and 24 grams per quarter pound of meat. You do not need more because you exercise or less because you loaf. If you get more than you need, the excess is burned as ordinary but expensive calories.

Ten ounces = 283.5 grams, so that is a misunderstanding of something. Do not rely on that advice.