hello
welcome to hcm
dear patient
i am happy that you are aware of this contagious condition.
if you father is on treatment with antitubercular drugs than with in maximum 9 days of treatment he will not be spreading the disease any more.
if treatment not started kindly start it as soon as possible and dont worry about the spread to you after starting the treatment.

here is some advise that your father must follow to not to spread infection if he is not yet started the tb treatment or not yet finished 9 days of medication.

Stay at home. Avoid going to work or school or sleep in a room with other people during the first few weeks of treatment for active TB. Doctors should be able to issue a sick leave for a certain duration if you work (these are the periods that TB is contagious).

* Ensure adequate ventilation. Open the windows whenever possible to let in fresh air. Avoid going in crowded places. Let there be enough ventilation.

* Practise good hygiene: Wash you body regularly, brush your teeth, wear clean clothes and keep your environment tidy and clean.

* Cover your mouth. It takes two to three weeks of treatment before you're no longer contagious. During that time, be sure to cover your mouth with a tissue any time you laugh, sneeze or cough. Put the dirty tissue in a bag, seal it and throw it away. Also, take adequate measures during the first three weeks of diagnosis and treatment as this will help lessen the risk of transmission, remember it is only you that specifically knows you have TB. After the active phase of TB, you can expect to keep your job, to go to school, to stay with your family, and to lead a normal life. However, you must take your medicine regularly to be sure of a cure and to prevent others from being infected.

i hope this answer all your doubt

take care
regards
Dr. vikas poddar