First of all jaundice is not a disease.It is a symptom.
Please check whether your brother was screened for
Obstructive jaundice or haemolytic jaundice or HEPATITIS or HIV or
leptospirosis or malaria or dengue fevers.
Other investigations like
ultra sound abdomen,widal test, complete blood picture,urine for bile salts,bile pigments,
urobilinogen also should be done.
If only these above mentioned levels are high, that can be treated just by taking rest,having fat free diet,fresh juices,glucose drinks, vitamin B12 supplements.preparations containing
ursodeoxycholic acid.
Last but not least , try to have faith in doctor treating your brother.If you don't believe you can change and consult a doctor who is well known for these kind of treatments.
Thank you