Hi Mickey,
Hb of 6 is nothing to get excited about. Your son is showing typical signs of being Intermedia that his Hb is hovering around 6-7.
You have already told us that your child was diagnosed Major and not Intermedia. However, know that Intermedia is a bit complicated and does not show up in the regular methods that are used for diagnosing the type of Thal. unless a DNA test has been carried out to identify the exact Intermedia mutation.
So, unless your child has undergone DNA, it is most probable that he was misdiagnosed as Thal. Major.
Anyway, the good news is that Intermedias respond nicely to HbF inducers that make the overall Hb go up. This is exactly what is happening to your son. It is most probable that Rodex is nothing more than a HbF inducer.
I wish you all the best, that this medicine is sufficient for your son that he does not require frequent blood transfusions and I hope that you will be able to manage his Intermedia superbly with the help of this medicine.
Take care, Peace!