Thanks for writing to us.
If your mom has lung TB for which she is taking TB medicines than she needs to continue that.
If your doctor has done CT scan
of brain than they should be able to make a diagnosis. If they could not make a diagnosis on MRI or CT scan than Biopsy
of the lesion would help them to come to a definite diagnosis. Unless & untill it is very clear that the tumour in brain is what , it is very difficult to treat a patient without diagnosis. So kindly follow your doctors advise.