Dear Kamlesh, the officials haven't mentioned the percentage required for NEET MDS but the eligibility criteria set by them mandates a candidate to hold a Bachelor’s Degree from a college recognized by NBE  in order to apply for the exam .NBE will be announcing NEET MDS eligibility criteria with the announcement of NEET MDS 2020 notification.

Candidates need to satisfy the eligibility criteria stated below pertaining to Academic Qualifications -

• Applicants must possess a Bachelor’s degree in Dental Surgery or a provisional passing certificate in BDS from any Indian dental university/college recognized by Government of India as per the Dentist Act 1948 or else they must possess an equivalent qualification recognized by Dental Council of India (DCI). The dental college recognition from Government of India must be made on or before October 31, 2017.
• INTERNSHIP/EXPERIENCE: All candidates should have completed or be in the process of completion the one-year rotary internship or practical training on or before March 31, 2019. The internship/training done in the respective dental college is approved or recognized by Government of India.

All the best

Hope this helps