what are metal nitrosyls how are they prepared in inorganic chemistry?

Answer 1

One method is the addition of NOBF4 to a transition metal complex.

Answer 2

Niscal, Navin, Prashant and Vivek Mungle...
A family too much involved in chemistry...

Some questions are reasonable even tough to answer but in effect you are requiring from us to write up a whole text-book.
I am sure you can find the answers in your own textbook for questions like this one or for others that require figures (like the one with the spectrum)...