@Mr. Mishra, I am not sure. One more thing, I didn't get any UV spectra around 500 nm and surface roughness (Ra) of my sample is very low (less than 1)
I wouldn't expect any SERS from TiN surface; as for Au or Ag nanoparticles, SERS is observable in 10-100 nm range in case of spherical particles. If you want to use roughened surface, typical size of protruberances shpuld be in the same range. You can also check out our paper about SERS observed on the rough surface with thin metal coating (maybe, you will be able to observe SERS after sputtering some gold onto your TiN substrate) - DOI:10.1007/s11837-015-1494-5