When ba non college form release
Hello Shiv,
I am assuming you are talking about the Correspondence courses of DU. In 2017, the application dates were Jul-August, and were extended till September with late fee.
For 2018, the query window of the School of Open Learning (SOL) is here: https://sol.du.ac.in/my/admission_issues.php
Do keep checking the links posted for the definitive date of application.