I have my site in office 365 and profile page under about me (me.aspx) showing wrong organization webpart? Can we remove or hide the organization webpart using master page or inject css? Or Please suggest?

Well if all the my site collections are created you are badly stuck, if they are not yet created then you can browse to mysite host site and delete that webpart from the page. you need to use http://siteurl/mysitehost/pages/home.asps?contents=1 from this contents page just remove the webpart.

If site collections are already created follow below:

http://www.c-sharpcorner.com/UploadFile/prasham/sharepoint-deleting-the-web-part-from-page-using-powershell/

http://nikcharlebois.sharepointspace.com/Blog/Lists/Posts/Post.aspx?ID=11