Is uterus size of 11.1 x 5.5 x 6.2 cm consider normal or enlarged with several small fibrosis? what are treatment options?

Fibroids in the uterus are fairly common. Your uterus size is not all that big. So you may not require any major operation right now unless you have excessive bleeding from your menses. There are more than one ways to mange the fibroids. Seek advice/second opinion from a second gynecologist. Besides Hysterectomy there are other alternatives to manage this problem.

Presumably you mean fibroids rather than fibrosis. Fibroids are very, very common and usually asymptomatic. Your uterus is roughly 2 to 3 times normal size but that is not significant in itself. If you are having symptoms (pain, heavy or irregular bleeding, pressure, urinary problems, infertility) then talk to your gynecologist about treatment options, but otherwise no treatment is indicated.