Sujal, the official website for MCC, in its provisional merit list for Ayush courses in 2019, defines EWNO as EWS Category. And we know that EWS stands for Economically Weaker Section. So EWNO also carries the same meaning. You can check that at: https://www.medicalcounseling.nic.in/aacccpg/home/ShowPdf . It might also be considered as EW with NO sub Category.