Unfortunately, I don't think it's as easy as simply increasing your protein intake. While it is possible to gain lean mass in a state of ketosis it's very difficult, complicated, and probably not the best for the average person (T2 or not).
Ultimately, insulin is essential in weight gain (whether healthy or not). That's why bodybuilders eat fruit immediately after their workouts....to spike their insulin levels and deliver amino acids to their muscles. I found this article on the website here:
http://www.diabetes.co.uk/building-muscle-with-diabetes.html
I think it's ultimately very good information. However, many modern sources now believe it's better to eat carbs immediately AFTER a workout rather than before. Even still, the average person probably won't realize a difference eating them immediately before vs. after.
On one hand, eating too many carbohydrates can spike insulin levels to an unhealthy level in a T2.
On the other hand, lean mass and exercise both aide in combating insulin resistance.
In my (untrained) opinion, it's a matter of controlling your carbs (rather than keeping them absent from your diet): slowly increasing your intake until you begin to gain weight, and knowing when (and when not) to eat carbohydrates.
While I'm not a T2, I do have personal experience (pre and post T1 diabetes) intentionally spiking my insulin levels to promote lean mass gains. I can tell you that it is incredibly effective especially now that I can directly control when and how much insulin I want to give myself.