According to RVNL, the detailed estimates have already been sanctioned for this in July/August 2014 and TDC is March 2016. I have been after this project since it was announced in the 2013-14 budget, I have been sending RTI queries to RVNL regarding this and received the latest reply with above remarks in Oct 2014. Check the latest RTI reply here :
/blog/post/1253322