Start submitting your website to many quality web directories. Directory submission of links has proved to be the most effective means of acquiring a lot of back links. It is the number of quality back links you have that's going to affect your site's PR in the near future.

Can you please provide me some website listing who exchange links and have "software outsourcing" and Offshore software Development" as keyword search.

Here is what you may be looking for: http://www.mexabet.biz/Computers___Internet/Software/. The site is only one month old but has over 500 back links, including many PR4 sites.

This is how google gives page rank on your site.

http://pr.efactory.de/e-pagerank-algorithm.shtml

Very informative link. Thanks for bringing up the link, as it might help a lot of people to understand PR algorithm.

and here is the formula i m searching

I don't really think that article is up to date. Page rank formula is being changed constantly, and you should concentrate on quality content, and high page rank websites, rather than low quality directories. Good luck.

i think you can submit your site to blog directories. this will diffinately bring traffic to your site.

Google interprets a link from page A to page B as a vote, by page A, for page B. Google looks not only at the sheer volume of votes; among 100 other aspects it also analyzes the page that casts the vote. However, these aspects don’t count, when PageRank is calculated.
PageRank is based on incoming links, but not just on the number of them - relevance and quality are important (in terms of the PageRank of sites, which link to a given site).
PR(A) = (1-d) + d(PR(t1)/C(t1) + … + PR(tn)/C(tn)). That’s the equation that calculates a page’s PageRank.