Here are a couple of articles from the Indian newspaper "the Hindu" about the locomotive:
NMR to get second oil-fired steam loco
Second oil-fired steam loco for NMR rolls out
This locomotive (the second one built) appears to be pretty much a copy of the original SLM-built X-class rack-and-adhesion engines built in the 1950s'. SLM and their successor DLM had tried to interest India in purchasing new, modernized versions of these engines for several years but never could reach an agreement. Here's an artist's rendering of DLM's proposed version: