Best phone for around 15k. No size preference, just something that doesn't lag.

1. Budget?
Less than rs15000
2. Display type and size?
Any size
3. Dual sim?
Preferred
4. Preferred choice of brand?
5. What camera option you want (flash, front facing camera)?
6. Preferred operating system? (Android, iOS, Windows Phone, etc).
7. Preferred connectivity options (3G, 4G ready).
8. Primary use of handset (multimedia, camera, internet, gaming etc)?
9. Any specific mobile phones in consideration?
10. Any other info that you want to share

4G ready, something with good software that'll just work, no lags.