Why Is My Site Not Ranking in the Search Engines?

Can someone tell me that Why Is My Site Not Ranking in the Search Engines? Site is 3 months old.

Thanks in advance!

You need good seo for offpage develop your website.Follow my some tips below:
1. create huge amount of backling in the high PR dofollow site.
2. Post daiy what you post
3. Discuss forum about your site
4. Social media marketing
5. Article and directory submission.