Dear Vaibhav

No official information with regards to the total number of students who appeared in NEET MDS 2018 has yet come in the public domain. At most, we can wait for the merit list (if it gets released by NBE for NEET MDS) to get an estimate of the number of students who appeared for NEET MDS 2018. 

However gauging from previous year numbers, about 25-30k students would have appeared for NEET MDS 2018 this year. 

Hope it helps.