Karmayog has compiled an extensive listing of organisations that are working in the flood areas and are accepting donations. See Here

There are organisations doing relief material collection in all major cities and several smaller ones. A couple of specific requests from there: A doctor involved in relief work in Patna requests specific medicines needed by women --> here

There is a request for doctors by AID India to work with their partners in Bihar --> here

Doctors for You wants to send 1500 doctors to work in the flood-affected areas for 3 months. They are requesting financial support for the doctors, as well as medico  and non-medico volunteers --> here