The Malayalam and Tamil Root Zone Label Generation Rules for International Domain names have been released for public comments. See the announcement from ICANN. This was drafted by the Neo-Brahmi Script Generation Panel (NBGP), in which I am also a member.

Your comments on the proposal for the Malayalam Script Label Generation Rules for the Root Zone (LGR [XML, 18 KB] and supporting documentation [PDF, 998 KB]) can be submitted at the feedback form till Nov 7 2018.

My earlier blog post on Internationalized Top Level Domain Names in Indian Languages has some detailed information about this.