How to make my site comes by Auto completion in google?

[SteveO]

Autocomplete is actually based more on traffic instead of SEO, and Google is cracking down pretty hard on SEO to prevent no-name crap sites from spamming the top of the search results when there are other sites that have far more traffic than yours. Focus on getting more legitimate traffic through your site and get it ranked on Alexa than on SEO and getting your site ranked over actual legitimate sites that have more traffic than your site.