If you have done D.El.Ed from NIOS, you can apply for the IGNOU B.Ed entrance exam. Because D.El.Ed from National Institute of Open Schooling (NIOS) is validated by The National Council for Teacher Education (NCTE).

Admission to the B.Ed program at MS University Tirunelveli is according to the norms of NCTE, Tamil Nadu State Government. You can apply through online/offline mode. The required eligibility for the program is graduation in a relevant discipline from a recognized university. 

While applying you will need identification proof, scanned photos, signature, transfer certificate, caste certificate, mark certificate, and birth certificate.