chose arduino board

i am an engineering student and planing to make my final year project using arduino . I want help in selecting my arduino board. my project is "arduino HID keyboard". i wass planing to buy ardruino uno for the same. Is it possible to make this project using arduino uno ?

Sure.
http://forum.arduino.cc/index.php?topic=99.0
Google Arduino HID for other hits. Need Arduino from 2010 on with Atmega8U2 or 16U2 for USB/Serial interface.
Cannot be done with FT232 chip for USB/Serial.

Possible, but there's better choices. A Leonardo or Micro would be much better. You don't need to buy any more parts or hack the support chips on the board.

An easier route might be to use a Leonardo as the Arduino core for this device natively supports HID keyboard/mouse class.

thank you very much for the quick reply.
can i buy this one ?
http://www.flipkart.com/arduino-uno-r3-original-made-italy-box/p/itme5cfuqjcbjtyc?pid=ETYE5CFTFM7HERR4&ref=L%3A2897329863390218796&srno=p_4&query=arduino+uno&otracker=from-search

2 out of 3 replies recommend a Leonardo. You can make your own choice.

actually after development of my project i want to shrink my project in attiny85 IC. i know how to do this using arduino uno R3. but is it posible using arduino leonardo ? all projects developed by arduino uno are possible to develop using arduino leonardo ?

Attiny85 does not have USB support. How would that part of the project work out?

http://codeandlife.com/2012/03/03/diy-usb-password-generator/

vkvk1993:
actually after development of my project i want to shrink my project in attiny85 IC. i know how to do this using arduino uno R3. but is it posible using arduino leonardo ? all projects developed by arduino uno are possible to develop using arduino leonardo ?

Thats not they main question.
The question is:
All project developed by arduino uno or leonardo are shrinkable to atiny85?

Well, leonardo and arduino uno (dfu mode) have native usb while tiny85 doesnt. Yes, you can use the driver for atiny you mentioned but the code changes a lot between leonardo/uno and atiny.

Projects for Leo can be shrunk justlike those for fir the uno, provided the tiny has the features you're using. They're all 8bit avrs, so the differences are just what peripherals and pins they have. For example, if you want to do usb stuff, you can't shrink it to use a chip without usb support like the tiny85 (just like you couldn't shrink a project to an attiny 85 if you needed 20 pins)

vkvk1993:
actually after development of my project i want to shrink my project in attiny85 IC.

I light of this new information I would suggest you think about something like the Adafruit Trinket where it is easy to program from the IDE but is the correct target device.