My tsh level showing 9.1. my doc did an anti tpo check value is normal (26). also did thyroid scan, it is also normal. Doctor didn't prescribe any medicine. Bit confused what could be reason for high TSH

Low thyroid. Although most thyroid disease is caused by an autoimmune disorder, some people's thyroid may just not be functioning well. You need to get this test repeated plus getting thyroid hormone level at the same time to make sure this was not a lab error. It may be a good idea to consult an endocrinologist as well.
Hypothyroidism . TSh being elevated is highly accurate to make the diagnosis of hypothyroidism. You have low levels of thyroid hormone circulating in ur bloodstream and therefore your tSH is high -- trying to stimulate the thyroid to make more thyroid hormone. You ought to get a second opinion if ur MD is not initiating thyroxine replacement therapy. Also u likely have symptoms of hypothyroidism - .
See endocrinologist. All laboratory results need to be interpreted in the clinical context and the doctor who ordered the tests is usually in the best position to do that. Having said that, Your TSH level indicates thyroid insufficiency and you may wish to consult an endocrinologist. At a minimum you need to get free T4 test done.