Adsense never specify how many post or how old your website, as long as you think your website is good enough and able to provide quality content and click, then it is the time for you to submit your site to adsense
It's not depend on Posts. How old is your site ? What is your language ? 6 months old and English is the best way But, you can use these 2 ways: http://www.k3lvinmitnick.com/2011/10/new-way-to-create-google-adsense.html
7 unique and quality post with a clean website will get you Adsense, domain age should be atleast 3 months !
Now in India it is very difficult to get approved for adsense... i am rejected many times so i changed my whole blog's content but then also it is not getting approved. can anyone tell me why ?
I think blogger works faster,because its owned by google and google wants to make money off you using their service.