Can you tell me on which basis Google provides Page Rank? And, how can I increase page rank for the web site?

Back links are the important role to convert your Page Rank. Google wants to get back link calculation from difference websites for your website which is decided your PG.

This question you should ask google directly, nobody else know the correct answer but google itself. But just like NAGARASAPANDI said, backlinks means something in caculating, that's for sure.

Just READ the forum this question has been asked and answered multiple times