Sounds to me like you're doing pretty well. Entertainment sites don't always do well with AdSense, because their users aren't shopping.

There are no sales in the websites. its purely content oriented with text based articles and photo galleries.

That's what I would have thought. So you're doing well, considering.

Browse here for tips and experiment with placement, colors, # of adblocks, etc, but you are doing well already, at least in my opinion.

how much do you think i can earn if i use adsense in a better way?

Is your CTR above or below 1%?

The entertainment AdSensers here will then tell you how that compares to the accepted industry average however you don't seem to be doing that badly:-)

Maybe you meant 10 million pageviews a month, in which case $4,000 a month is a bit low but reasonable, given the niche and the country.

There's something wrong with these numbers somewhere.

There is something really inconsistent with the numbers

You say you earn $4000 per month at $26 eCPM. That means 153,800 impressions put out in a month

153,800 impressions per month means 5,100 impressions per day not 9 million impressions per day? quite some difference

If you really want advice, you really need to give the correct data!