The demonstration came in response to a call from the Indian Medical Association (IMA).
The IMA held a "Delhi Andolan", which included a march by the medical fraternity from Nirman Bhavan - which houses the Health Ministry - to Jantar Mantar in the heart of the capital.
Doctors and experts have alleged that Section 32 of the proposed NMC Bill will intensify quackery by rural medical practitioners, private medical practitioners and others.
IMA President Santanu Sen said the "government will have blood on its hands" if Section 32 of the NMC Bill 2019 was not removed.
He said the addition of Section 32 legalized quackery by empowering community health providers to practice medicine and this would endanger the lives of people.
Rajan Sharma, another IMA leader, said if Section 32 was not removed, 3.5 lakh community health providers would be legalized to prescribe drugs.
The IMA is also opposing other provisions in the Bill including the decision to couple NEXT and NEET and regulation of fee by the NMC for 50 per cent seats in private medical colleges and deemed universities.
"The NMC Bill compromises patient care and patient safety. It also violates the constitutional principles of right to democracy, federalism and equal opportunity," the IMA said in a statement.
The NMC Bill has been listed for discussion in Parliament on Monday.
The Bill proposes a common final year MBBS examination, to be known as National Exit Test (NEXT), for admission to post-graduate medical courses and for obtaining license to practice medicine.
It would also act as a screening test for foreign medical graduates, official sources said.
Besides this, the National Eligibility cum Entrance Test (NEET), common counselling and NEXT would be applicable to institutes of national importance like AIIMS in order to achieve a common standard in medical education in the country.
( With inputs from IANS )