Finally I got working wmlbrowser plugin for my N900 MicroB Browser.

Go to app. manager and Create new app. catalogues as below:

Catalogue name : Diablo maemo extras
Web address : http://repository.maemo.org/extras/
Distribution : diablo
Components : free non-free

Go to Download and find "wmlbrowser (v. 0.7.20-2)" Plugin and install.


* Also I install firefox wmlbrowser add-on in MicroB browser,
https://addons.mozilla.org/en-US/firefox/addon/62

* I dont know which plug-in are actually working but now I can open wml sites in my N900 MicroB Browser.