BibTeX
Copy the unsrt.bst style file to your document's directory and rename to, say, unsrt-custom.bst. On GNU/Linux this can be achieved with
cp $(kpsewhich unsrt.bst) ./unsrt-custom.bst
Edit the unsrt-custom.bst file. Add the function
FUNCTION {output.newline}
{ duplicate$ empty$
'pop$
'output.nonnull
if$
"\newline " write$
}
and adjust the FUNCTION {misc} accordingly
FUNCTION {misc}
{ output.bibitem
format.authors output
title howpublished new.block.checkb
format.title output
howpublished new.block.checka
howpublished output.newline % <-- changed
format.date output
new.block
note output
fin.entry
empty.misc.check
}
Run the chain pdflatex → bibtex → pdflatex → pdflatex on the following sample document.
\begin{filecontents*}{\jobname.bib}
@misc{keyword,
title = "Title",
howpublished = "\url{link}",
}
\end{filecontents*}
\documentclass{article}
\usepackage{url}
\begin{document}
\cite{keyword}
\bibliographystyle{unsrt-custom}
\bibliography{\jobname}
\end{document}
Enjoy the output.

BibLaTeX
biblatex comes with “batteries included” in the sense, that you can control the appearance of the style directly from the document. To achieve your desired style we modify the representation of the url field
\DeclareFieldFormat[online]{url}{\newline\url{#1}}
where we have used the new @online entry type, which is best suited to cite online sources. The full example boils down to the below document and the following chain of commands: pdflatex → biber → pdflatex → pdflatex
\begin{filecontents*}{\jobname.bib}
@online{keyword,
title = "Title",
url = "link"
}
\end{filecontents*}
\documentclass{article}
\usepackage[sorting=none]{biblatex}
\DeclareFieldFormat[online]{url}{\newline\url{#1}}
\addbibresource{\jobname}
\begin{document}
\cite{keyword}
\printbibliography
\end{document}

\bibliographystyle{unsrt}– Shika93 Jun 04 '16 at 08:54