The strike has crippled health services mainly in the Indian capital and the states of Uttar Pradesh state and Bihar. Rallies and protest demonstrations by doctors and medical students have also hit public hospitals in several other states.
Senior doctors have been running emergency services in the hospitals.
The doctors and medical students oppose the government's plan to increase quotas for lower-caste students in state-funded medical, engineering and other professional colleges from 22.5 percent to 49.5 percent, the AP reports.
They also have been demanding appointment of a committee of experts to review the existing affirmative action program.
The government has offered to increase enrollment at state-funded professional colleges so the number of seats available to "general" students wouldn't be cut under the affirmative action program.
Despite laws against discrimination, India's lower castes - 80 percent of India's 1 billion people by government estimates - are still at the bottom in most social indicators such as education, income, and employment.