Which are best phones in india under RS10000 or 10k(i like windows phones but i'm bored of my lumia 520)?

You can go for below mobiles:

# Samsung Galaxy S Duos 2 @ Rs. Rs. 10067
# Sony Xperia M @ Rs. 11456
# Lenovo Ideaphone A706 Rs. 9395

In first 2 both are quite similar in hardware. You can go as per your personal choice samsung vs sony

# Samsung Galaxy S Duos 2
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Powered with Android v4.2 (Jelly Bean)
63.1x121.5x10.57 mm
Yes, 5 Megapixel camera
768 MB RAM internal storage
CPU - 1.2 GHz Cortex-A9, Dual Core

Sony Xperia M
=============
OS - Android OS v4.1.2 (Jelly Bean)
Screen - 4 inches Screen
Camera - 5 MP
Internal Momory - 1 GB RAM, 4 GB Storage
CPU - 1 GHz Dual Core Krait 200 Processor

In the budget of 10K, Lumia 520 is the best option for window phone, but you already have the same so opt for Lumia 525 which is launched by Nokia and have upgraded RAM. This Window phone is reachable in the 10K.
http://www.ebay.in/itm/281242764092

And if you can consider an Android Smartphone and that is from Sony than Sony Xperia E Dual is the best mobile.
http://www.d2hshop.com/sony-xperia-e-dual.html

Hope this suggestion helps you in buying!

I would like to suggest you micromax canvas blaze. The device has great features. It runs on Android v4.1 Jelly Bean OS.Micromax Canvas Blaze MT500 has a 5-inch TFT capacitive touchscreen display with a resolution of 854 x 480 pixels. You can check other features here - http://www.91mobiles.com/micromax-canvas-blaze-mt500-price-in-india

You can go for Xolo Q700.
Its price is Rs. 8500.
4.5 inch IPS display.
1.2 ghz quad core(Mediatek?
1gb ram. 4 gb rom
2400mah battery.
5 mp rear camera.vga front

Sony Xperia M
Motorola Moto G
Samsung galaxy S Duos 2
Micromax Canvas 2.2 A114