The Criteria of rank

Pramod quality is in your hands ; quantity can be checked through many websites which give you a html ratio of your blog.  

You are very right, Mr. Pramod. The real problem lies in quantification of qualitative aspects. You can't actually measure quality, no matter what method of measurement you use. IndiRank uses a number of so called - "benchmarks" to measure the overall quality of blogs, as you rightly mentioned some - Alexa rank, Links, frequency, to name a few. There's MozRank too. Most of these "benchmarks" have been designed with the thought that people visit and interact with sites that are good, and provide good viewer interaction. The better your site, in terms of visitor interaction and contents, the more is the time the visitor will stay on your blog, and the more frequently he/she'll visit your site, thus making it popular. Search engines, Website Ranking services, use such advanced techniques to measure the overall quality of the websites. They do measure the time a typical visitor spent on your site, the number of pages the visitor visited in each session (every time a visitor visits your site, a new session is created and finishes when the visitor has left your site completely), the level of indulgence the site provides.

But how the quality can be judged?

I don't know the answer to this question but if the question is 'Can quality be judged using a computer program', then the answer may be partially yes.

A similar question - 'Can aesthetics be evaluated by a computer?'.