navn29,
This page has a good explanation of Myelodysplastic/Myeloproliferative Neoplasm, Unclassifiable.
Since hydroxyurea hasn't let your brother become transfusion independent, it doesn't sound like a long-term solution, and your brother is much too young to be on only supportive care. Have his doctors mentioned the possibility of a stem cell transplant? Where he could be treated may depend on that possibility.
Because MPN-UC is rare, it's hard to find experts. I suggest that you use the
NCI Clinical Trial search page to look for trials for myeloproliferative disorders. Click "In City/State/Country" to limit the trial location to centers in India (or any other country your brother might go to for treatment). Even if you don't find a trial that suits your brother, you can display the Trial Site information and learn which hospitals or research centers are running the trials. Those centers are likely to have doctors with expertise in treating MPN.