Looking for Graphic Cards for MMRPG (Dota 2,CS:GO) and Apps like Autocad,Revit Within my PC configuration

USAGE FROM MOST TO LEAST IMPORTANT: Gaming (Dota 2 , FIFA 14 and some Simulator Games),watching movies, Autodesk Architectural Suite 2014,Revit.
CURRENT GPU:
SYSTEM SPECS:
System Information
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Machine name: AKIL-PC
Operating System: Windows 7 Ultimate 64-bit (6.1, Build 7600) (7600.win7_gdr.110622-1503)
Language: English (Regional Setting: English)
System Manufacturer: INTEL_
System Model: DH55TC__
BIOS: BIOS Date: 09/23/09 11:58:43 Ver: 08.00.10
Processor: Intel(R) Core(TM) i3 CPU 530 @ 2.93GHz (4 CPUs), ~2.9GHz
Memory: 4096MB RAM
Available OS Memory: 3894MB RAM
Page File: 3864MB used, 3919MB available
Windows Dir: C:\Windows
DirectX Version: DirectX 11
DX Setup Parameters: Not found
User DPI Setting: Using System DPI
System DPI Setting: 96 DPI (100 percent)
DWM DPI Scaling: Disabled
DxDiag Version: 6.01.7600.16385 32bit Unicode
DRIVER DETAILS:

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Display Devices
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Card name: Intel(R) HD Graphics
Manufacturer: Intel Corporation
Chip type: Intel(R) HD Graphics (Core i3)
DAC type: Internal
Device Key: Enum\PCI\VEN_8086&DEV_0042&SUBSYS_00368086&REV_12
Display Memory: 1696 MB
Dedicated Memory: 64 MB
Shared Memory: 1632 MB
Current Mode: 1600 x 900 (32 bit) (60Hz)
Monitor Name: SyncMaster B2030/ B2055PLUS(Digital)
Monitor Model: SMB2030
Monitor Id: SAM063D
Native Mode: 1600 x 900(p) (60.000Hz)
Output Type: DVI
Driver Name: igdumd64.dll,igd10umd64.dll,igdumdx32,igd10umd32
Driver File Version: 8.15.0010.2993 (English)
Driver Version: 8.15.10.2993
DDI Version: 10
Driver Model: WDDM 1.1
Driver Attributes: Final Retail
Driver Date/Size: 2/19/2013 13:44:12, 8314368 bytes

COUNTRY : INDIA
PREFERRED WEBSITE(S) FOR PARTS: Flipkart
OVERCLOCKING : Dont Know about that
SCREEN RES: 1600 X 900

COMMENTS:Hope i have posted sufficient information,If not do specify the details which i need to provide.So I currently don't own a Graphics Card and looking forward to buy my First Graphics Card for my Computer .I just want to use a Graphics Card on current system and not looking forward to buy new processor at this point of time.So my budget range would be <75$ or 5000 rs.(Indian Currency) and moreover i want to run the games and apps on medium configurations or resolutions.thanks in advance.