Currently I Am A Patient Of Hyperthyroidism/Over Active Thyroid. I

Currently I am a patient of Hyperthyroidism/Over Active Thyroid. I came to known about this on January 2018.After that I consulted with a Doctor of Endocrinology Dept. I did several blood tests and hormonal tests and started taking medicine from March 2018. Currently my prescribed medicine is Carbimazol 5mg and Indever 10, Barbit 30. I'm taking this medicine from last 6months.Every month I'm doing the same Blood and Hormonal Tests( TSH, T4) and after seeing my test reports Dr. change my Drug dose according to the test reports.
Now my concern is, Can I join to GYM with this thyroid problem??
Will it cause any hamper to my treatment/my body??
Because I was a Regular gym going person from last 3years. For this Thyroid problem I loss Huge amount of body weight (around 12kg) for that i stopped to go to gym from last year.Now I want to start again, My Dr. is not answering this question properly or Im not getting what he is trying to say. Im so much confused what to do.Please help me.