1.what is exact each partition size of /data ,/system ,/cache size?
Data: im on the 16gb vercion so...12.9GB
2.i want to my dual sim version and cheapest i get it in 14k from flipkart.is this price is ok? or anybody know any other cheap place.?
I cant help you with this one, but the price of Moto-G shoud be the equivalent of 175 US Dolars (may vary with 8gb and 16gb)
3.is moto g have auto brightness?
Yes and its awesome !
4.moto g play 1080p hd video smoothly?
Why would you want a 1080p video on a 720p screen ! .
but it does play 720p (and 1080p) video smoothly
5.usb otg work in 4.4.2?
yes it does, you need to download a app like StickMount its really usefull
*I played a movie from a USB flashdrive the other day , good stuff
6.hd game run without any lag?
Again why would you like 1080p games on 720p screen but..you can go to this threat for more info
7.moto g have official cm11?
i hope this answer your questions !
Sorry for my bad english