Thank you for the explanation, Nuwwara. Let me add a little touch…
You use “râh” to make a statement. It’s more or less an equivalent of: “The thing is…”.
Etymologically speaking, and please bear in mind that I am not a linguist, I think that it comes from the MSA verb: ra2â, to see. Râh = It/he is seen. So it’s like introducing a fact that you are sure about or witnessed.
Don’t let this mess up your mind, and take it as I said, as a way to introduce a statement.
By the way, it does get conjugated:
Rânî mâ jâyyâsh = I am not coming.
Râhâ m3âya = She is - in fact - with me.
I hope that it makes sense. Otherwise, don’t hesitate to ask again.