If u want to buy a new graphic card here the suggestions :
(i spent a lot of time for a perfect answer)
DDR3 & GDDR3 Graphic cards :
1 NVIDIA GeForce GT 520 2 GB DDR3 Graphics Card
2 AMD/ATI Radeon HD5570 1 GB DDR3 Graphics Card
3 XFX AMD/ATI Radeon HD 6450 1 GB DDR3 Graphics Card
4 AMD/ATI Radeon HD 6570 2 GB DDR3 Graphics Card
5 AMD/ATI Radeon HD 5670 GPU 1 GB GDDR3 Graphics Card
GDDR5 Graphic cards :
1 AMD/ATI Radeon HD6750 1 GB GDDR5 Graphics Card
2 GeForce GT 440 1 GB GDDR5 Graphics Card
3 AMD/ATI Radeon HD 6670 1 GB GDDR5 Graphics Card
Here r the list of Best GPU under Rs 6,000...
1.Sapphire AMD/ATI Radeon HD 6450 1 GB DDR3 ----------- Rs 2587
2. XFX AMD/ATI Radeon HD 5450 1 GB DDR3 Graphics Card ------- Rs2470
3.Sparkle NVIDIA GeForce GT 520 1 GB DDR3 ---------Rs 2646
4.PowerColor AMD/ATI Radeon HD5570 1 GB DDR3 --------Rs 3293
GRAPHIC CARD WHICH I PERSONALTY RECOMMEND :
1.Asus NVIDIA GTS 450 1 GB DDR3 Graphics Card ----Rs 5955
2.XFX AMD/ATI Radeon HD 6670 1 GB DDR3 GPU ------Rs 5674
3.Sapphire AMD/ATI Radeon HD 6750 2 GB DDR3 ------Rs 6050
I'll highly recommend u to buy 3.Sapphire AMD/ATI Radeon HD 6750 2 GB DDR3 .because this is the best graphic card which let u to play all high end games up to date. with max settings.
info about 3.Sapphire AMD/ATI Radeon HD 6750 2 GB DDR3.
1.04 billion 40nm transistors
TeraScale 2 Unified Processing Architecture
720 Stream Processing Units
36 Texture Units
64 Z/Stencil ROP Units
16 Z/Stencil ROP Units
DDR3 memory interface
PCI Express 2.1 x16 bus interface
DirectX® 11 support
Shader Model 5.0
DirectCompute 11
Programmable hardware tessellation unit
Accelerated multi-threading
HDR texture compression
Order-independent transparency
OpenGL 4.1 support1
Image quality enhancement technology
Up to 24x multi-sample and super-sample anti-aliasing modes
Adaptive anti-aliasing
16x angle independent anisotropic texture filtering
128-bit floating point HDR rendering
ATI Stream acceleration technology
OpenCL 1.1 compliant
DirectCompute 11
Accelerated video encoding, transcoding, and upscaling4,5
Native support for common video encoding instructions
ATI CrossFireX™ multi-GPU technology6
Dual GPU scaling
ATI Avivo HD Video & Display technology7
UVD 2 dedicated video playback accelerator
Advanced post-processing and scaling8
Dynamic contrast enhancement and color correction
Brighter whites processing (blue stretch)
Independent video gamma control
Dynamic video range control
Support for H.264, VC-1, and MPEG-2
Dual-stream 1080p playback support9,10
DXVA 1.0 & 2.0 support
Integrated dual-link DVI output with HDCP11
Max resolution: 2560x160012
Integrated HDMI 1.4a with Stereoscopic 3D Frame Packing Format, Deep Color, xvYCC wide gamut support, and high bit-rate audio
Max resolution: 1920x120012
Integrated VGA output
Max resolution: 2048x153612
Integrated HD audio controller
Output protected high bit rate 7.1 channel surround sound over HDMI with no additional cables required
Supports AC-3, AAC, Dolby TrueHD and DTS Master Audio format
ATI PowerPlay™ power management technology7
Dynamic power management with low power idle state
Ultra-low power state support for multi-GPU configurations
Certified drivers for Windows 7, Windows Vista, and Windows XP
Choose my answer the best if i deserve it !