All my songs and videos are present in NTFS partition, as a result whenever i search for music in dash it results nothing. So how do i tell dash to look for content in specific folder rather than looking only in home folder.
Add your music to your player's library.
I think this question is very similar to this one. The Unity music lens uses different Scopes - Banshee by default, I gather - to provide results. This is part of the lens spec. Banshee ONLY provides music results that are inside its library, so anything else won't show up.
In any event, for ease-of-use, I'd recommend creating a symlink to your NTFS partition inside your music folder:
Edit: Just found a duplicate - here. Answers are quite similar.