It is up to you, as long as you think this is the right time, then go ahead Nothing wrong to put the adsense on your site early
place them now but place them neatly so that they don't annoy your readers, with only 20 visits/day your earning are going to be close to nothing so don't check your adsense account every hour cause it will only cause disappointment and you will loose interest and hope in adsense, instead place them... and again place them neatly and just leave it there, continue to work on you site and provide great quality articles and soon enough you will see your earningse start to raise as you visitors do and when you less expect it you will be earning between $10-$20/day. Hope that helps
I suggest you to place adsense on your blog if you have already an adsense account. If you don't have one ,you should wait till adsense team approve your application. As you are in India, you may need a website /blog with minimum 6 month old to get approved. Keep writing more articles on your blog and attract more visits. best of luck.