Is there any time limit for writing comments on research article?
Yes, you can publish comments both informally (e.g. on a blog) and formally (by writing a paper that references the 2009 article) irrespective of when the original work was published. Much older articles get referenced and followed up upon.

The only issues to be aware of are:


The authors are somewhat less likely to notice and react to the comments.
Research on the topic may have gone on and your comments may be "old news", or already superseded of their own.