I have a site and want to install a of blog on my site . What is better onsite blog creation or offsite blog creation ?
By 'offsite blog creation', do you mean you are going to use new domain to install the blog ? If yes, its better.
Your question is a bit confusing. If you want to install a blog on your current domain then its always a good idea but one thing you have to keep in view to update the blog page regularly then only it will be beneficial.