I have a blog related to loan(http://www.onlinecashadvance.blogspot.com/) if i create a site related to same category and giving links from the blog to the site will it boost the site?
yes if the other blog has a great number of traffic.. somehow you can get traffic. but not for sure.. is your KW has a good number of prospective searcher?
You will need to optimize effectively those keywoprds for your site, yes your blog will help somewhat for exposure of your newer site like you can place links, ads etc.
Did you mean, not yet indexed by SEs? If so, then you should be doing that first. If it does not rank high well at SEPRs, then you need to build quality back links The strategy you suggested can help.