There is a press release that mentions that the coins on the occasion of Nabakalebar Rath Yatra will be released. See Press Release
However looks like given the year 2015 is lined up with quite a few coins, we may not see this theme.
The article on the Govt website also has the design for the proposed coins and stamps.
16-Jan-2016: There is controversy over the design of the coin. More details here. Thus the coin release looks to be further delayed. 6-Feb-2016. There is more news with STJA refusing to give opinion.
28-May-2016: More News.