1) Organic promotions - People will promote your app and get you app downlaods. Influencers promotions etc.
2) I can also get you rating and review along with downloads. Which means people will download and give 5 star rating as well.
3)The retention rate will be good. One month retention for most of the downloads.
4) Speed as you specify - can get 20,000 downloads and rating and review in a week
5) Rate depends on work. If only download it can be 20 rupees, if rating and review also required then 30 rupees
6) India as of now